Human Errors: A Panorama of Our Glitches, from Pointless Bones to Broken Genes

by Nathan H. Lents

While eating a varied diet is a good strategy to acquire all the elements we need, including iron, it must be carefully varied, in such a way that iron-rich foods are not paired with those that prevent iron extraction.

The age of sexual maturity is thus the first limiting factor in reproductive capacity, a phenomenon that is true in all species, not just humans.

The entire human reproductive system is littered with inefficiencies and poor design. To recap: Humans mature late, conceal female ovulation, have trouble making healthy sperm and eggs, create embryos that don’t implant or that have missing or extra chromosomes, initiate pregnancies that aren’t successful—and even when everything goes right, both babies and mothers die in childbirth at shockingly high rates.

There is an entire subfield of economics, known as behavioral economics, that has arisen in recent decades to explore these biases. One of the founders of the field, Daniel Kahneman, won a Nobel Prize for this work and has explained many of our biases in his popular book Thinking, Fast and Slow.

In order to avoid having to thoroughly analyze each and every situation you find yourself in, your brain establishes rules based on past experience that help you make quicker judgments. Saving time has always been a priority, and the brain has evolved to save time whenever it can. Psychologists refer to these time-saving tricks as heuristics.

Even when people know that their brains tend to get something wrong, and even when they’re given all the information needed to get things right, there are some mistakes that they’ll just keep on making.

the Forer effect is often called by another name: the Barnum effect, after P. T. Barnum, who famously said, “There’s a sucker born every minute.”

the only valid way to do a lineup is to have every single person in it—the suspect as well as the foils (as the paid lineup actors are known)—match every part of the physical description that is given by the witness.

It may be true that people enjoy playing at the tables, but the explanation that is often given after losing money—that it was really just about having fun—is an ex post facto justification that allows them to deny, even to themselves, that they have made poor choices.

the only real way to win is simply to quit altogether when you’re ahead, but almost no one can do that. People who are that powerfully governed by logic are unlikely to find themselves in the casino in the first place.

People become less careful when they have more resources, which only ensures that they will soon part ways with those resources.

the gambler’s fallacy is deep-seated in the human psyche and sometimes disguises itself as intuition.

We also have an anchoring bias. People give a great deal of value to the first piece of information they receive, regardless of its trustworthiness. This leads all further information to be valued not in strict terms but relative to the original.

People often combine the power of anecdotes and the confirmation bias to support their positions on any number of social issues.

Young people, particularly but not exclusively males, take insane risks in order to advertise their “fitness.” This does not necessarily mean displaying physical prowess, although it can certainly be that. The term fitness display comes from the study of animal behavior and refers to ways that animals communicate to potential mates, as well as potential rivals, that they are forces to be reckoned with. It’s a way of saying, I am so powerful that I can do this dangerous thing and still come out okay.

sexual selection sometimes leads to the evolution of ridiculous impediments to survival that exist purely so the male can display feats of strength.

young females experience stronger sexual attraction to males who display risky behaviors, particularly those involving feats of physical strength.

while it might be tempting to think that the recent increase in the age of first reproduction among humans will reduce costly displays of fitness among young men (and make smart, sensitive young men more attractive to their peers), this is unlikely to have any quick impact. An evolutionary transformation like that would require a genetic difference between risk-takers and safe players, followed by many generations of selective pressure. Absent those factors, humans can count on adolescent boys doing stupid things for some time to come.

much of the public-awareness programming aimed at reducing rates of smoking, drinking, drug use, and other risky behaviors may be totally backward in its approach. While explaining the risks of drugs to a high school student might seem like a logical way to dissuade him from trying them, it probably has the opposite effect. Explaining that drugs are risky could make them more attractive to kids, especially young boys.