Chapter 12

The Relevance of the Past to the Present

ON FEBRUARY 19, 2021, Senator Bernie Sanders of Vermont was asked his views about the then-pending nomination of Neera Tanden to be director of Office of Management and Budget. Because Tanden had been sharply and personally critical of Sanders when she worked for former secretary of state Hillary Clinton some years earlier, questions arose about whether the tone of her criticism of Sanders, as well as of many Republicans, would persist were she to become director of OMB. In response to the questions to him, and to Tanden’s pledge to be “radically different,” Sanders said, “I worry less about what Ms. Tanden did in the past than what she’s going to do in the future.”¹

Two years earlier, on February 25, 2019, Trump administration press secretary Sarah Sanders (no relation to Bernie Sanders) cautioned those in attendance at a White House press conference not to believe the allegations being leveled against the president by his former lawyer and “fixer” Michael Cohen. “It’s laughable,” Sanders said, “that anyone would take a convicted liar like Cohen at his word.”²

Stepping back from the political combat that framed both of these events, the comments of Bernie Sanders and then of Sarah Sanders raise important issues about the evidentiary significance of past acts—and not only criminal convictions—in reaching conclusions about someone’s subsequent or likely behavior. Should the fact that Tanden had used strong and personal invective in the past be taken as evidence of her proclivity to do so again in the future? Does the fact that Cohen lied in the past make it more likely than we would otherwise suppose that he is lying now? Is Cohen’s past lying evidence of his current lying? In insisting that Cohen should not be believed now because he had lied in the past, Sarah Sanders was asking her listeners to rely on the venerable adage “Once a liar, always a liar.” Or, to the same effect, “Leopards never change their spots.”

But are these slogans sound? Or was Bernie Sanders on firm ground in saying, possibly sincerely and possibly not, that past actions may not be very good evidence of future or even current behavior? And is the thought behind “Once a liar, always a liar” applicable not only to lies, liars, and leopards, but also to human behavior in general? Did Virginia governor Ralph Northam’s racist performance in blackface while in medical school make it more likely than otherwise that he would engage in racist acts or make racist decisions while in office?³ Should President Biden’s mandatory F for plagiarism in a law school course in 1965, combined with his subsequent unattributed uses of the language of other political figures in some of his own campaign speeches, be taken as evidence against the veracity—or the originality—of anything he says now?⁴ Does Martha Stewart’s 2004 felony conviction for lying to federal officials provide evidence for distrusting her recipes or the products she recommends?⁵

Consider also tennis at the highest professional level, where players frequently falsely claim an injury in order to secure an additional time out, or sometimes to avoid continuing to compete in a match they are destined to lose.⁶ If some player claims a non-obvious injury, should the referee (or the doctor, for that matter) take into account that player’s past record of false injury claims in assessing the likelihood that this time it is a genuine injury? The same question arises in professional golf, where it is sometimes contested whether a player has intentionally adjusted the ball or the terrain in order to make a subsequent shot less difficult.⁷ If the tournament officials are unsure about the truth of an accusation of this form of cheating, is the accused player’s past record of rules infractions relevant for the officials in making their decision now?⁸ And if the player is the president of the United States, does a record of cheating on the golf course provide some evidence of likely dishonesty in the performance of official presidential duties?⁹

Often in such cases, a common argument against using someone’s previous behavior as evidence for what they might have done now is that what is past is past. Just because someone has done something before does not mean that they will necessarily do it again, and especially under different circumstances, so the argument goes. But would those who make that argument accept a late-night ride from someone who had been convicted on three previous occasions of driving while intoxicated, or, criminal convictions aside, from someone they knew to have been involved in multiple automobile accidents? And why did the New York Times, in reporting on a 1991 subway derailment that killed five passengers and injured another two hundred, think it important to inform its readers that the motorman operating the train had some months earlier ignored a red signal while operating his train, and that he had, still earlier, been reprimanded several times by the Transit Authority for violation of the Authority’s rules?¹⁰ The Times, we suspect, believed that the motorman’s past conduct was relevant in determining whether on this occasion he had been acting negligently, or had been once again violating the rules of the Transit Authority. Whatever we may think of the more complex examples of Governor Northam and President Biden and Martha Stewart—examples that likely are colored by political or personal preferences of admiration or animosity—few people are likely to fault the Times for thinking that the motorman’s past acts are relevant to evaluating his claim of innocence on this occasion. The same goes for the tennis pro who says that this time the pain is real, or the professional golfer who professes innocence when accused of less-than-honorable behavior.

Past acts are commonly considered to be relevant in predicting future behavior, which is why convicted child molesters do not get hired as camp counselors or TSA agents, and why confessed plagiarists rarely secure positions as college professors. And although evidence is crucial both in predicting future behavior and in determining the events of the past, the immediate focus here is on the relevance of past acts in attempting to determine under circumstances of uncertainty the facts of something that has already happened. Prediction is indeed important, but so is determining what occurred in the past or what is happening now under conditions of uncertainty. Still, it is worth bearing in mind that for all of these inquiries, whether forward-looking, backward-looking, or present-looking, the question is whether what someone has done in the past is evidence of what they did later, what they are doing now, or what they might do in the future.

The Law’s Peculiar Attitude

One reaction to questions about the relevance of past acts to assessing the likelihood of subsequent behavior is to wonder how anyone could possibly doubt that past behavior is evidence, and often good evidence, of subsequent behavior. Past acts are of course relevant, as Sarah Sanders and all of us know. Common experience and everyday decision-making provide countless examples of our willingness to use earlier actions as evidence as to what someone might subsequently have done. If a friend asks me to believe that he has been cheated by a cashier at a local store, I am more likely to believe him if I had been cheated by the same cashier at the same store a month ago. True, Governor Northam’s political supporters might argue against making much, if anything, about his past lapses, as would those who are fans of Martha Stewart, or politically sympathetic to President Biden, or would like to believe Michael Cohen. But parents do not hire convicted child molesters as babysitters. Banks do not employ security guards who have been released on parole after having served time for bank robbery. And it is pointless to try telling your insurance company that your three previous accidents should not cause them to raise your rates or cancel your policy because the accidents you have had (or caused) in the past do not show that you are more likely than anyone else to have or cause accidents in the future. Your insurance company knows that your past record is relevant to assessing your subsequent behavior, and most of the rest of us operate in the same way when we decide who to trust, who to believe, and who to hire to fix our cars or repair the plumbing. Faced with a question about who did something now, or what someone did now, our fingers quickly point to the person who has done something similar in the past, or to what some person has done in the past. Captain Renault in Casablanca spoke not only for countless police officers, but also for most of the rest of us, when he memorably referred to rounding up “the usual suspects.”

Yet however odd it seems to ignore past acts in trying to figure out whether someone has done something on this particular occasion, that is exactly the typical and long-standing practice of the legal system. Rule 404(b) of the Federal Rules of Evidence—a rule that governs trials in federal courts, that serves as the model for the rules of evidence in most states, and that reflects a long-standing approach throughout the common-law world—provides that “evidence of a crime, wrong, or other act is not admissible to prove a person’s character in order to show that on a particular occasion the person acted in accordance with the character.”¹¹ Put aside the issue of character for the moment. We will return to that shortly. Stripped of the character question, what this rule says is that past acts, including but not limited to past crimes and past wrongs, cannot be used to show that someone committed that kind of act on the occasion in question. That the defendant has committed three bank robberies in past years cannot be offered in evidence by a prosecutor trying to prove that the defendant has committed the particular bank robbery he is now charged with committing. In a typical lawsuit emerging out of an automobile accident, and in which both drivers claim that the other driver negligently caused the accident, the plaintiff is not permitted to show that the defendant driver has been found liable for negligent driving on multiple previous occasions. And if Michael Cohen were now to be charged with perjury for allegedly once again lying during a court proceeding, the jury will never hear about his past conviction for pretty much the exact same crime.

Is the law being irrational? Why would the legal system insist on excluding evidence of what anyone with any common sense knows to be relevant? If banks will not hire convicted bank robbers as security guards, why can’t juries take past bank robbery convictions into account in trying to decide whether someone committed the bank robbery with which he is now charged? If insurance companies can use our past accident records in setting our rates, why can’t courts use those same accident records in seeking to judge whether some accident was our fault?

Not surprisingly, the law has several responses to what at first glance seems perverse. One response implicitly recalls a theme common in more than a few movies.¹² Someone, typically a juvenile male, has gotten into trouble as a result of, say, stealing a car or committing an assault during a gang fight. He goes to prison, and, upon release and seeking to “go straight,” looks to find a job. But employer after employer asks whether he has a criminal record, and, learning that he has been convicted of a crime, refuses to hire him. And he then objects that this is unfair, and that his past acts should not be held against him. He has, he complains and pleads, already “paid his debt to society.”

In excluding past crimes and other wrongs that have produced some sort of penalty (including a judgment in a civil lawsuit based, say, on negligent driving), the law might be understood as agreeing with our unfortunate parolee. If someone’s past conviction and imprisonment for a crime can now be used against them when they are charged with a different crime, are they not being punished once again for the past crime? If having to pay money as a result of a verdict in a civil suit following a finding of negligent driving can then be used in a subsequent civil suit again charging negligence, is the driver at risk of being penalized once more for his past negligence? It is unfair, so the argument goes, to use someone’s past wrongs against them in this way. Having already served their time or satisfied a civil judgment, the wrongdoers have paid their debt to society. And the debt having been paid, they are entitled to be judged on a clean slate. To use a previous conviction in a subsequent trial is to impose an additional penalty precisely because the evidence of the past wrong increases the probability of liability for this one. The legal system, in excluding these past acts as evidence, is sympathetic, refusing to allow past convictions or past wrongs to be used for the purpose of now attempting to prove that someone did something similar on a subsequent occasion.¹³

Perhaps recognizing that this justification for ignoring past acts tends to persuade neither insurance companies nor very many ordinary people, the legal system and the law of evidence have another and arguably stronger justification for refusing to infer subsequent behavior from previous acts. And this justification explains why the legal system’s refusal to use previous acts as evidence for the existence of a subsequent act applies not only to crimes and other wrongs but also to behavior in general, criminal or not, good or bad. Yes, the law appears to say, previous acts are indeed relevant to making determinations about subsequent behavior. And perhaps in an ideal world those previous acts would be given some limited amount of weight as evidence. But this is not an ideal world, and “some” is not the same as “all.” Giving previous acts some weight is not the same as treating the inferences from those past acts as indisputable. After all, people who have negligently caused accidents in the past are not negligent every time, and so they might not have been negligent this time. Just because some people have lied previously does not mean that every single statement they make is a lie. And similarly for people who have committed crimes in the past. So even if previous acts are relevant, they are typically not conclusive. “Once a liar, always a liar” overstates things, and “Once a liar, more likely than others to be lying now,” even if less catchy, comes closer to reality.

Yet although past acts do not conclusively prove current behavior, the legal system worries that people think otherwise. Especially when the people who think otherwise are judges and members of juries. Accordingly, the legal system has long assumed that jurors, and even judges, actually do believe in the “Once a liar, always a liar” adage, and believe it literally, however exaggerated it may be. Or once a thief, always a thief. Or once a bad driver, always a bad driver. And so on. In other words, although past acts appear to have some value as evidence of subsequent behavior, the law of evidence worries that judges and juries will overvalue these past acts. The legal system fears that the person charged with burglary who has in the past been convicted of burglary will be presumed of course to have committed this burglary. Sarah Sanders, after all, wanted her audience to take Michael Cohen’s past perjury as conclusively proving that he is not telling the truth now. But although Cohen’s past perjury might give us some reason to be skeptical about the truth of what he is saying now, and although someone’s past burglaries might give us some reason to doubt that person’s claims of innocence when he is charged with committing a burglary now, these doubts are hardly conclusive. Consequently, the legal system, fearing that jurors and even judges will take past acts as conclusive proof of present behavior, excludes using those past acts as evidence. Better to give those past acts too little weight, the law says, than allow judges and jurors to give them too much.¹⁴

In addition to reflecting a fear of overvaluation, the legal system also tries to prevent juries, and perhaps also judges, from punishing people for what they have done in the past and not for what they are being charged with in the present. Although related to the additional penalty implicitly imposed when evidence of past acts increases the probability of conviction or liability for the act now being tried, the concern here is different. Here the concern is that people will be punished once again for the prior acts or even for acts for which they were not punished but that are not the subject of the current proceedings. Courts are supposed to try people only for the acts with which they are now charged, but there will always be the temptation to punish for something else, especially if the something else seems especially horrid, and especially if the something else has thus far escaped punishment. Fearing that judges and jurors will succumb to this temptation, the legal system compensates, and perhaps overcompensates, by using the law of evidence to keep jurors, especially, from even knowing about acts other than the one now being tried that might be thought by these jurors to deserve punishment, or to deserve additional punishment beyond whatever punishment was already imposed.¹⁵ Indeed, the legal system’s treatment of character and of past acts may reflect an important theme in the law of evidence—that more evidence is not necessarily better, and not even more relevant evidence, especially if juries or even judges will misuse or be misled by that evidence. Sometime in the law, less evidence is thought to produce greater accuracy, and this lesson may well be valuable, even if rare, outside of the legal system as well.

Character—Good and Bad

Consider again the provision of the Federal Rules of Evidence quoted above. The rule does not say simply that past acts cannot be used to prove current behavior. The rule takes the additional step of providing that past acts cannot be used to prove that someone has the kind of character, or disposition, that would lead them to commit acts of this kind. If someone has been found negligent in three previous automobile accidents, we might think that they are careless people, or at least careless drivers. And if they are careless drivers, they are more likely to be careless in the future, more likely carelessly to cause accidents, and more likely to have carelessly caused the accident that is now at issue. Sarah Sanders urged us to believe that Michael Cohen had the character trait of dishonesty—a trait, she insisted, that gives us reason to not believe anything he says.

Even with this additional step—from past acts to character to current acts, and not just from past acts to current acts—the law, in presumptively excluding the use of character as well as past acts, once again departs from what seems to be common sense. People are, most of us believe, careful or careless, honest or dishonest, punctual or tardy, sloppy or neat, selfish or considerate, rude or polite, and so on. “He’s always late.” “She can be trusted with money.” “He’s short-tempered.” We make these judgments about people all the time, and we make them on the basis of their past acts. And having made these judgments of character or disposition, we use them predict what they are likely to do in the future and to reach conclusions about what else they might have done in the past. If I have been caught with my hand in the cookie jar on four previous occasions, I become the leading suspect for the current cookie theft because my past acts produce the inference that I have the disposition to steal cookies. It is not simply that I sometimes or frequently steal cookies. It is that I am a cookie stealer. Or maybe just a thief. Or just dishonest. That is my character. Those are my dispositions.

Such conclusions about a person’s character are precisely what the legal system prohibits judges and juries from using. For the reasons just described, the law typically does not allow judges and juries to engage in what, technically, is called propensity reasoning.¹⁶ Judges and juries are not permitted to conclude that a person’s past bank robberies or past negligent driving show them to have a propensity for robbing banks or a propensity for bad driving. Such propensities—however real they seem to be, however consistent with common sense they seem to be, and however much they are supported by empirical research—cannot be taken into account in deciding whether someone acted in a way that is consistent with that propensity on a particular occasion.

In worrying about the use of character in this way, or, more accurately, about the overuse of character, the legal system tracks some of the central themes of modern academic experimental psychology.¹⁷ In particular, psychologists have long been concerned with the relative importance of dispositions, or traits, on the one hand, and situations, on the other, in determining how people act. Dispositions are deep-seated characteristics of personality or character, and include such things as introversion and extraversion, selfishness and altruism, honesty and deceptiveness, conscientiousness and laziness, and so on. And for a long time many psychologists believed, along with many (most?) ordinary people, that such dispositions are the chief determinants of human actions.¹⁸ There are dishonest people who are inclined to lie and steal, so it was said, just as there are aggressive people who are likely to cut you off on the highway, egoistic people who will talk about themselves all the time, amoral people who will engage in selfish behavior, and cautious people who will never take chances. Accordingly, if one were looking for evidence about what happened on some occasion, it would be very useful to know about the dispositions—the characters, the traits, the personalities—of the people whose actions were under investigation. If two people were in a fight, and the police wanted to know who started it, then knowing that one of the combatants was generally aggressive and short-tempered while the other was shy, cautious, and tolerant would be good evidence about who was the likely aggressor—about who started the fight. The same goes for parents or teachers who are adjudicating competing claims of “He started it!” by the two combatants in a playground, backyard, or backseat scuffle. In such instances, knowing the traits of the participants would help decide what really happened. Or so the so-called dispositionists would have had us believe.

In the 1960s, Yale psychologist Stanley Milgram famously conducted a series of experiments in which seemingly normal people were induced to commit seemingly abnormal acts—applying increasingly painful electric shocks, in the most notorious of these experiments—because of group pressure or a desire to please an authority figure.¹⁹ Psychologists then became increasingly committed to the view that it was the situation rather than the dispositions of the people involved that was the principal determinant of human action. If you wanted to know who started the fight, you would want to know what the disagreement was about, whether the combatants had a history with each other, whether there were other people present or involved, and much more. All of these things would be part of the situation in which the fight started, and such facts could provide much better evidence of who started the fight than merely knowing the character or dispositions or traits of the fighters. And to ignore all of these, it was said, was to commit the fundamental attribution error—to attribute far too much explanation for an action to dispositions and far too little to the situation.²⁰

These days most psychologists recognize that explaining behavior is not only a matter of understanding dispositions or traits, and not only a matter of understanding the situation. Instead, human behavior is a function of the interaction between dispositions and situations.²¹ Different people react to the same situations in different ways, and thus it is a mistake to think that it is all about the situation. There really are aggressive people who will start a fight under the same circumstances (the same situation) in which others, with less aggressive personalities, will walk away. But even people with more or less the same dispositions (or traits, or personality) react in different ways to different situations. If you wanted to know who started the fight, therefore, you would want to learn as much as you could about the personalities of the fighters, but you would also want to learn as much as possible about the full situation in which the fight started. Knowing all of this, or at least much of it, would provide better evidence of who probably started the fight than would the evidence provided by dispositions alone, or by the situation alone.²²

A good example of the issue, in the context of just this common question of who started the fight, comes from a widely publicized 2003 Massachusetts event. A Harvard graduate student named Alexander Pring-Wilson was walking home very late one evening after having consumed a considerable quantity of alcohol with several friends. As he was walking home, he was spotted in Cambridge by several local individuals, who also were drinking, and who were sitting in a car while waiting outside a pizza shop for their pizza to be ready. Words were exchanged, including the loud observation by one of the individuals in the car that Pring-Wilson was “shit-faced.” Pring-Wilson took umbrage at this apparently accurate observation, which was accompanied by other expletives. Tempers flared, a fight ensued, and one of the individuals in the car, Michael Colono, wound up being stabbed by Pring-Wilson. The stab wounds turned out to be fatal, and Colono, the victim of the stabbing, died in the hospital shortly thereafter.

At this point the stories diverge. Samuel Rodriguez and Giselle Abreu, companions of the deceased Michael Colono, testified that Pring-Wilson came over to the car, pulled one of the individuals out of the car, and started the fight. Pring-Wilson, however, claimed that two of the people in the car jumped out of the car and attacked him, leading him to take out a knife for use in self-defense. And thus, with tragic consequences, the question was the familiar one of who started the fight. If Pring-Wilson’s story was true, then he acted in self-defense and had committed no crime. But if the deceased’s companions’ story was true, then Pring-Wilson, as the instigator, was guilty of murder, and he was indeed so charged and tried in the Middlesex County Superior Court.

At the trial Pring-Wilson’s lawyer attempted to present evidence of the victim’s character—specifically that the victim, Michael Colono, was, and was well known to be, a volatile hothead who was the kind of person who would start a fight. The trial judge, relying on the law’s traditional aversion to character evidence, initially refused to allow the evidence of the victim’s character to be heard by the jury, and the jury, knowing nothing of Colono’s character, then convicted Pring-Wilson of voluntary manslaughter. Pring-Wilson thereafter moved to have the verdict set aside, arguing that an intervening decision of the Massachusetts Supreme Judicial Court required the trial judge to admit evidence of Colono’s character.²³ The trial judge agreed and set aside the conviction, a decision which was upheld, against the Commonwealth’s appeal, by the Supreme Judicial Court. The court concluded that a victim’s character could indeed be offered as evidence to show who was the likely first aggressor, a conclusion that is now an explicit exception to the federal rule quoted above, although that rule is not directly applicable to a Massachusetts state court prosecution.²⁴ At a second trial, the jury was unable to reach a verdict, and, Pring-Wilson eventually pled guilty to the lesser charge of involuntary manslaughter and served several years in prison. But this anticlimactic denouement is less important to us, if not to Pring-Wilson, than the way in which the case clearly presents the question of the extent to which someone’s character is relevant in the determination, under conditions of uncertainty, of what actually happened.

The issue in Commonwealth v. Pring-Wilson, the technicalities of the law apart, is a relatively straightforward question of evidence. We don’t know who started the fight, and there are two conflicting stories. It would seem useful, therefore, to know something about the characters and past activities of the fighters, not because we are interested in those activities themselves, but because those past activities provide evidence as to what might have happened now, just as Sarah Sanders wanted us to believe that Michael Cohen’s past untruthfulness provides evidence about whether he is being untruthful now. As a result of Pring-Wilson’s case, and the earlier one that had led the trial judge to grant the new trial, it is now the law in Massachusetts, as it is in federal courts and in states whose rules of evidence are modeled after the federal rules, that where the question is one of identifying the first aggressor, the character of the victim is deemed admissible, and so too, in response, is evidence about the character of the alleged perpetrator. But although the events of this case provide a useful and vivid laboratory for considering the extent to which character and past behavior (which is, after all, what people use in attributing some character to a person) should be used to reach conclusions about what likely happened now, it is important to bear in mind that this case and the treatment of “victim character” present an exception to the general rule. And the general rule, at least in the courts, is that past acts cannot ordinarily be used be used to try to prove what someone did or did not do or did or did not know.

Outside the Courts

What makes the law interesting here is precisely the way in which the judicial system’s general aversion to past act evidence and character evidence seems so at odds with common sense and with how people make decisions in everyday life. Sarah Sanders knew that the best way to cast doubt on Michael Cohen’s story was to call attention to his proved past acts showing him to be someone with a less than scrupulous concern for the truth. And in doing so, Sanders recognized that people do not follow the Federal Rules of Evidence in making their normal and everyday decisions. If you contract food poisoning after eating at Sammy’s Steakhouse, you are likely to think that Sammy’s concern for restaurant cleanliness is lacking, even though it is of course possible that this was a onetime consequence that could not be attributable to any of Sammy’s practices. And if you read on Yelp or Tripadvisor or any other such site that three other customers have complained about food poisoning at Sammy’s, you would likely conclude that Sammy has an unsanitary and thus unsafe kitchen, even though such past reports and past complaints would likely not be admissible in court were someone to sue Sammy’s for negligently serving a contaminated salad.

In this and many other non-courtroom settings, the question is more about predicting future behavior than it is about discovering the truth about some past act. But the evidentiary question of what happened in the past is similar in this regard to the question of what will happen in the future. Even those aspects of the law that are concerned with prediction will use past acts to predict future behavior. Judge Richard Berman of the US District Court in New York denied bail to then-accused and now-deceased child molester Jeffrey Epstein because Epstein’s past acts, while on bail, indicated to the judge that he would do the same thing were he to be released on bail this time. And outside the law the reasoning process involved in prediction of future events is similar to the reasoning process of trying to determine what happened in the past. Past food poisonings at Sammy’s Steakhouse will lead most of us to predict a greater likelihood of food poisoning in the future—or tonight, when we are deciding where to eat—than for restaurants with a “cleaner” history. But those same past food poisonings will also lead us to point the finger at Sammy’s if someone who contracts food poisoning today ate at three different restaurants yesterday, one of which is Sammy’s and two of which have never been known to serve contaminated food. Or consider the common situation, the far milder version of the Pring-Wilson case, in which two squabbling siblings each protest to their parents that the other started it. Most parents will be more inclined to believe the child known to be less aggressive, or known to be more truthful, even as they recognize that this fundamentally evidentiary determination based on character or past acts might be mistaken on this occasion. And those same parents will also treat the same past acts as relevant for prediction of future behavior, as when they must decide the age at which the respective children will be allowed to have something that can be used as a weapon—a penknife, say—or the age at which the children will be allowed to go unaccompanied to concerts or parties.

As these examples suggest, it is unrealistic to suppose that, outside of the courtroom, people will or should ignore past acts in trying to determine what happened, or what will happen. And it is not just that refraining from using past acts in this way—by citizens, by politicians, and by insurance companies, among many others—is unrealistic. It is irrational as well. Past acts and the character they reveal are genuinely relevant in a vast number of instances aimed at determining what happened, as the barrage of examples offered above is designed to show. And they are relevant in the same way and to the same effect as they are in the legal system and, for that matter, in most of our everyday evidential reasoning.²⁵ That is, past acts typically make our belief in the existence of some act more likely if we know about the past acts than if we do not. Consider, for example, the recent accusations that three sitting United States senators—Senator Richard Burr of North Carolina, Senator Dianne Feinstein of California, and then-senator Kelly Loeffler of Georgia—had unlawfully sold securities based on information received in confidential briefings about the effect of Covid-19 on the economy. With respect to Senator Burr, however, although not to the other two, the accusations come against the background of his previously having traded securities of companies connected with his senatorial responsibilities, although these latter trades were plainly lawful.²⁶ The question, then, is whether these prior acts, somewhat different from but also somewhat similar to the acts for which Senator Burr is now being investigated, are relevant in determining the truth of Burr’s denial that his recent and suspect trades were based on inside information. There is a good chance that those prior acts would not be admissible as evidence in a trial charging Burr with criminal or civil violations.²⁷ But they might well have been “admissible” for voters deciding whether to vote for Burr in an election, for the Senate in deciding whether internal discipline is appropriate, for a president considering whether to nominate Burr to an appointive office, or for a corporation considering whether to put Burr on its board of directors. All of which is to say that the legal system’s common exclusion of past acts, and the character they manifest, need not be determinative of the relevance of those acts and that character as evidence of the truth or falsity of Burr’s denial of culpable knowledge, or of many other questions of disputed fact, in a wide range of contexts with a wide range of consequences outside of the legal system.

Although the evidentiary relevance of past acts and inferences about character from those acts is as obvious as it is ubiquitous, the cautions embodied in the legal system’s approach should not be lightly dismissed, for they are applicable outside of the legal system as well. Most importantly, the tendency of people to overvalue past acts is real, and thus the need to counterbalance that overvaluation is real as well. Sarah Sanders wants us to take Michael Cohen’s past plagiarism as conclusively establishing that he is lying now, but that is too simple. Yes, there are reasons to be more skeptical of what Cohen says now than there would be of what the modern-day George Washington—he of the almost-certainly-apocryphal unwillingness to lie about chopping down the cherry tree—would say, but that skepticism should only go so far. This skepticism based on past acts is properly understood as a veracity discount, but it is not a discount to zero. If we are rational, we will recognize, Sarah Sanders’s urgings notwithstanding, that we might be inclined to make too much of past acts, and not enough of the possibility that people can change their ways, and not enough of potentially relevant differences between the past acts and our current concerns.

So too with the legal system’s concern that we not punish again those who have already been punished. A common complaint among those who have been through bankruptcy is that bankruptcy is not the fresh start that it is billed as being because the stigma of having been in bankruptcy follows post-bankruptcy efforts to obtain loans, mortgages, and often employment. Much the same might be said about having been held liable for causing an automobile accident, engaging in medical malpractice, or committing any number of other acts that might produce what at first seems like onetime civil liability, but that in fact stick to the originally liable individual like barnacles on the bottom of a ship—permanently annoying and all but impossible to remove.

None of this is to suggest that in making our daily decisions about who did what to whom, or about what happened, we should ignore the genuine relevance of similar past acts. Nor should we ignore the dispositionist side of the psychological debate between the dispositionists and the situationists. Dispositions, traits, characters—whatever we choose to call them—are real, and so is their value in helping us make decisions under circumstances of uncertain knowledge, just as knowing of Michael Colono’s traits helps us to reach conclusions about the actual facts of his fatal altercation with Alexander Pring-Wilson. Indeed, Pring-Wilson’s own traits and prior acts might have provided similar assistance had there not finally been a plea bargain.

Still, the legal system’s seeming reluctance—a reluctance admittedly softened by many exceptions—to allow past acts to be used to prove subsequent conduct should not easily be dismissed. At first it appears that the legal system is acting irrationally, and that its sharp departure from common sense is a good reason to ignore its approach when we make decisions in our nonlegal lives. But dismissing the law’s approach is too easy. As we have seen, there are sound reasons behind the law’s reluctance to use what so many of us use in our daily lives. And if it seems a bit much to go as far as the law goes when we have to decide which child started the fight in the backseat of the car seems, remembering why the law does what it does can often provide a useful corrective to making too much of past acts. As Sarah Sanders seemingly recognized, there is a strong appeal to using past acts or past wrongs to make decisions about who or what to believe now. Sarah Sanders implored us to recognize why the past matters. But she intentionally did not tell us why it might not.

Another Note on Profiling

All of the examples in this chapter share a focus on the past acts of an identifiable individual. What is the evidentiary import of what Michael Cohen, Martha Stewart, Michael Colono, and all of the others have done before? But it is worth signaling again, as I did in Chapter 10, the close connection between the questions raised in this chapter and the larger issue of profiling based on group characteristics, where some of the evidentiary inferences from group characteristics to individual acts are accurate but many are not, and where some of these inferences are benign and many are pernicious.

Consider again the malingering tennis pro. The question, for the match referee or for the doctor, is whether this tennis pro’s past acts of faking or exaggerating injuries should be relevant in determining whether this claim of injury is real. The evidence for the claim being accurate—for the injury being real—might come from what the player is now saying, from the way the player walks or runs, from the expression on the player’s face, and much else. And the evidence against the injury being real might include the fact that this very player has in the past faked injuries under circumstances very similar to the current one.

But now let us change things slightly. Suppose that this player has no prior history of faking injuries. Still, both the referee and the doctor know that tennis players in situations like these often do fake their injuries. In evaluating the player’s claim of injury, and the consequences that might flow from an injury, should the referee or the doctor take account of the fact that professional tennis players in situations like these often—or at least more often than other people—claim injuries that do not exist, or claim that their injuries are far more serious than they actually are? In other words, is it evidence against the existence of an injury, as claimed by this particular tennis player, that professional tennis players in general often fabricate injuries in similar circumstances?

Once we move beyond individuals and their past individual acts, the evidentiary weight to be given to evidence of this sort will plainly vary with the size of the class within which we place this particular person or event. If the particular tennis player, the legitimacy of whose injury we are trying to evaluate, is a thirty-eight-year-old male from some particular country, then statistics indicating that tennis players with these exact characteristics and from that country have a high incidence of fabricated injuries would seem to have a great deal of evidentiary weight, whereas statistics indicating that men have a higher rate of injury fabrication than do all players, regardless of gender, would be less weighty.

All of this is familiar to most people who have visited the doctor in recent years. More and more, physicians are interested in basing, or at least assisting, their diagnoses by this very kind of statistical data, often in the name of the so-called evidence-based medicine discussed in Chapter 2. Of course, all medicine is evidence-based, and has been for millennia. When physicians listen to their patient’s heartbeats, or test their reflexes, or look into their ears, they are using their observations as evidence of some condition. What makes this kind of evidence-based medicine different is that here the evidence, as with our example of the potentially malingering tennis player, comes not only from the individual, but from what we know about some class of which the individual is a member.

The crucial point here is that class-based evidence is still evidence. Doctors know it. Captain Renault knew it. We all know it. If a child comes home crying that he has been bitten by a neighborhood dog, and if one of the dogs in the neighborhood is a pit bull, the greater incidence of aggressiveness for pit bulls than for many other breeds will be some evidence, although hardly conclusive, that it was the neighborhood pit bull and not the neighborhood golden retriever that was responsible.²⁸

Although class-based evidence is evidence, there is another side of the story. The other side of the story is about the dangers, commonly associated with racial profiling, of too easily attributing to all members of a class the attributes that are possessed by the class on average, even if not by every member of the class. There is little harm if we take the class-based reliability statistics of certain models of cars—the Yugo from the former Yugoslavia and the Trabant from former East Germany come to mind—as evidence of the likely unreliability of a particular car. But when we do the same not for cars but for humans who are members of groups defined by race, religion, gender, age, sexual orientation, and much else, the issue becomes far more complex, and there are often sound reasons for refusing to use as evidence even the class-based characteristics that have some statistical basis. These and related complexities have been widely discussed and analyzed, but it is worth noting here that both the virtues of evidence-based medicine and the vices of racial and ethnic profiling emerge from the way in which, at times, the class characteristics of a class of which some individual is a member can provide some evidence about what that individual has done in the past, or is likely to do in the future. Indeed, and again recalling the discussion of evidentiary inference in Chapter 2, there is a sense in which all evidence is of this variety. When we believe that the person wearing a ski mask and running out of the bank with a bag has just robbed that bank, we do so because of what we know, or think we know, about the class of people wearing ski masks and running out of banks with bags, a class of which this particular person is a member. And when we side with Sarah Sanders and against Bernie Sanders in supposing that past acts are at least some evidence of current and future behavior, we are also, as with our masked and bag-carrying bank robber, engaged in class-based evidentiary inference. We worry about John Henry Wigmore’s published belief, discussed in Chapter 8, that women are less reliable witnesses than men because it is empirically unfounded and because it would be unjust even if not, but that cannot be a general worry about drawing inferences from classes of acts or events to individual acts or events. Doing so is what evidentiary inference is all about, and doing so for the inference from past to present is little different from the kinds of inference that evidence demands, even if, as with the use of past acts in courts of law, there may sometimes or even often be sound reasons for refusing to take into consideration what the evidence seems to suggest.