Intuitive behavioral genetics

Humans are inference generating machines. We use what we can to predict the character of other people, even the behavior of their relatives.

Written by Diana Fleischman

Imagine you’ve moved into a new neighborhood. You and your new neighbor, Jack, quickly build a friendly rapport and, after a couple weeks, you give him a set of keys to your house in case of an emergency. One day, on your way to visit him, you see a young guy stumbling out of Jack’s front door, a laptop in one arm, and a jewelry box in the other. He doesn’t seem sober. Suddenly Jack runs up and says to his son, “Stop it Pete! You told me you wouldn’t do this again!” Pete drops the goods and runs off. “Pete’s an addict,” Jack tells you. He changes his locks often, he explains, because Pete comes over and steals from him and his wife.

Who wouldn’t feel terrible for Jack? He seems like a good guy. Yet you find yourself rethinking giving him your house keys. Do you change your opinion of him at all because his son is an addict and a thief?

Questions about how much we can infer about a person’s morals based on their family lineage are back in the news after Jonathan Turley wrote an article for the Hill about Biden’s great great grandfather’s murderous ways. In brief, a Biden ancestor, Moses J. Robinette, got drunk, stabbed an unarmed man to death and was spared a prison term by a Lincoln presidential pardon. Turley depicts the Bidens as a sort of crime family who are buffered from the consequences of their actions by wealth and privilege. 

The article rankled many prevailing sensibilities. With another Trump versus Biden matchup looming, this criticism of Biden seems to pile on to more pressing concerns, like his cognitive ability and potential corruption. The article also implies that criminality is heritable- an idea that got so much pushback Turley disavowed this interpretation of his words and claimed his notion of the Bidens having been “naturally selected” to evade accountability was tongue in cheek. 

This is not the first time that there has been an attempted smear on Biden based on his relatives. Back in 2020 the Hunter Biden laptop scandal broke and was suppressed on social media. Shortly before the election, there was a scandal about Joe Biden’s son Hunter—leaked pictures, among other things, led many news outlets to revisit his alleged problems with drugs, erratic behavior, corruption and incompetence.

We know that humans are inference machines. With very little information, people can guess at rates above chance whether someone is a psychopath. With a 10-second video clip, people can correctly guess whether someone is gay 81 percent of the time. To many, “stereotype” is a word practically synonymous with “false,” but stereotype accuracy is one of the best replicated findings in psychology. When you don’t know someone very well, you can accurately infer a lot simply by knowing their ethnicity, sex, or country of origin. In both the case of Hunter Biden and Moses J. Robinette, media figures are pointing at a familial association, implying that it says something about Joe Biden’s character. And, even though Biden has been in politics for decades, the implication is that hidden aspects of his character can be known through these family ties. But how is this inference made? If, someone’s relatives are violent, immoral or corrupt how and why might this shade a person’s character?

Back to the parable of Jack and Pete.

You might be someone who thinks that the environment has a strong influence on people’s personality, and that having negligent or otherwise bad parents is a major way for people to become dysfunctional. In recent history, it was common to blame people’s parents for their ills. Since they were more involved in children’s lives, mothers were blamed more often than fathers for kids who grew up and lost their way. For decades, autism and schizophrenia were attributed to “refrigerator mothers”- a term for mothers who weren’t adequately warm and maternal or even abusive and neglectful. This attribution caused generations of parents, but especially mothers, to feel profoundly guilty for their children’s disorders. Back when homosexuality was considered a disorder, it was blamed on absent fathers. Now it’s common to say that addiction and criminal behavior are caused, in part, by absent fathers. By this logic, you might wonder if Jack’s bad parenting was in some way responsible for Pete’s dysfunction.

You could also change your assessment of Jack for genetic reasons. Behavioral genetics looks at where individual differences come from—whether from family upbringing and life experience, or genetic factors. Or from both - for example, parents could choose to buy more books because their kid shows a lot of natural interest in reading. 

For most characteristics, it looks like genetics are much more important than parenting. One large study found that, for adopted children, their rate of criminality was 12 percent if their biological parents were criminals but their adopted parents were not criminals—but just 6 percent if their adoptive parents were criminals and their biological parents were not. When both sets of parents, biological and adoptive, were criminals, the rate of criminality shot up to 40 percent. There is a similar pattern when it comes to drug and alcohol abuse. If we know that Pete is a criminal with a substance-abuse problem, his father Jack is much more likely to have these problems as well.

I’ll call this judgement we make about others, on the basis of their relatives, “intuitive behavioral genetics.” Research has shown that people aren’t bad at guessing how heritable certain human traits are. And, interestingly, it’s mothers of multiple children who are the best at guessing heritability. But, making this association plain is considered reactionary, and even eugenic. But, it wasn’t always so.

As Geoffrey Miller wrote, during the Victorian era the quality of a person’s family was once a major factor in the decision to marry:

The "good family" question always concerned genetic inheritance as much as financial inheritance. Since humans evolved in bands of closely-related kin, we probably evolved an intuitive appreciation of the genetics relevant to mate choice, taking into account the heritable strengths and weakness that we could observe in each potential mate's relatives, as well as their own qualities….Consider the possible reactions a woman might have to hearing that a potential husband was beaten as a child by parents who were alcoholic, aggressive religious fundamentalists. Twin and adoption studies show that alcoholism, aggressiveness, and religiosity are moderately heritable, so such a man is likely to become a rather unpleasant father. Yet our therapy culture says the woman should offer only non-judgmental sympathy to the man, ignoring the inner warning bells that may be going off about his family and thus his genes. Our culture alienates women and men from their own genetic intuitions.

You can see a similar inference from famous fictional Victorian detective and intuitive behavioral geneticist Sherlock Holmes in The Adventure of the Copper Beeches. Here Holmes infers that a father was likely to have committed a sinister crime because of his son’s gleeful sadism:

My dear Watson, you as a medical man are continually gaining light as to the tendencies of a child by the study of the parents. Don't you see that the converse is equally valid. I have frequently gained my first real insight into the character of parents by studying their children. This child's disposition is abnormally cruel, merely for cruelty's sake, and whether he derives this from his smiling father, as I should suspect, or from his mother, it bodes evil for the poor girl who is in their power."

One of the most common systems of governance in history was hereditary rule; for example hereditary monarchy where the eldest son of a king takes over when the king dies. Back before democracy was developed, intuitive behavioral genetics gave this hereditary rule some extra legitimacy. You might infer that if someone was a good and competent leader, there would be a pretty good chance that their close relatives, like their children, who have 50 percent of their genes, would also be good leaders. Or, at least if you know how to cope with one leader’s personality problems, you’ll probably be able to figure out how to cope under the rule of one of their close relatives.

Leadership may be even harder to define than criminality or substance abuse, and there are many different ways to become a leader. However, literature backs this up: leadership, like all other psychological characteristics, likely has a substantial genetic component. This is also a possible reason why there was so much focus on the paternity of the sons of kings. A child whose father was not the king would have less predictable characteristics. This may also be why royal bastards often ended up in prominent political positions. Even though they were formally illegitimate, people may have trusted that they had similar good leadership qualities to the father that sired them, they would have still benefitted from nepotism and they may have been more likely to have inherited characteristics that motivated them towards powerful positions.

Even in democracies, we see that the relatives of political leaders are more likely to end up political leaders themselves. For example, Shinzo Abe, Japan’s longest serving prime minister, is the grandson of a prime minister and a prominent politician. You can see similar patterns commonly in Eastern democracies like South Korea, the Philippines, Indonesia, Singapore, and Taiwan. You might put this down to just nepotism and name recognition. But that explanation could be missing the kernel of rationality inherent in political dynasties, the trust people bestow on family members of trusted politicians, and our tendency to ascribe certain psychological characteristics to notable families.

Intuitive behavioral genetics also sheds light on why prominent political families are so guarded about family members with psychological problems. The same intuitions that create trust can also sow distrust.

Consider Roger Clinton Jr, younger half-brother to Bill Clinton. Roger was given the nickname “headache” by the Secret Service and ultimately pardoned by Bill for cocaine possession. His various shenanigans could have made people more likely to see unbecoming characteristics in Bill Clinton. And, perhaps if the public had been more aware of Bill Clinton’s biological father, who had been married 5 times by the age of his death at 28, including to two sisters, we might have been less surprised by his behavior in office. 

Rosemary Kennedy, the younger sister of John F. Kennedy, was incapacitated by a lobotomy that was meant to cure her violent mood swings. There are many other stories of leaders, politicians, and celebrities who have taken to hiding embarrassing relatives, perhaps to stay in the good graces of the public.

It’s surprising that there is almost no research about how much we judge people based on their relatives, given the abundance of evidence showing that we make quick inferences about other people on the basis of little information. Some sociologists have looked into a related bias, the inaptly named “courtesy stigma”. If you associate with someone who is stigmatized in society, like someone with substance-abuse problems, schizophrenia, or a cognitive disability, that stigma can fall on you. “Family stigma” is one form of courtesy stigma.

People are more likely to think that a son or daughter is likely to have substantial difficulties if they find out the father of this person is in prison, depressed, or an alcoholic than if he is away much of the time, or elderly. Another study found that most people who had a family member with schizophrenia wanted to hide this information from others. Looking at attitudes towards close relatives of people with schizophrenia or drug addiction, respondents were more likely to blame parents for having sons and daughters with these dysfunctions but thought all close family members including brothers, sisters and sons and daughters “should feel ashamed” Because most sociological research still rarely considers the role of behavioral genetics, the implication is that humans stigmatize the close relatives of people with significant dysfunction for reasons of mere proximity, rather than because of a heuristic that these close relatives are very likely to share this dysfunction.

These heuristics played out during the 2020 presidential election. There was some mudslinging from both sides in an attempt to discredit both Biden and Trump through their family associations. The Lincoln Project, a political action committee with the aim of ousting Trump, posted a billboard of daughter Ivanka looking excited about COVID-19 death rates, implying, to my eye, a heritable psychopathy. 

Even in hindsight it’s unclear how much the Hunter laptop scandal had on Joe Biden’s election performance, especially through active suppression. Perhaps people were less likely to attribute Hunter’s problems to Joe’s genes or parenting because Hunter was in a significant car crash that killed his mother and sister and left him with a serious head injury. Or, Hunter may have caused some voters to have less trust in Joe Biden, leading to a closer election.

Similar to stereotypes, intuitive behavioral genetics can be used to ostracize or stigmatize without direct evidence against the individual. This is considered unfair and immoral to most people. This, along with the idea that heritable criminality is a debunked form of eugenics, means we are likely to disavow that we are making inferences in this way. However, it’s only natural that we would use every means necessary to ascertain the character of our leaders, especially when direct evidence about them is suppressed. 

Diana Fleischman is a writer and independent scholar. You can find her @sentientist. Much of this article was originally published in Nautilus.

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