Hunter vs. farmer hypothesis

The hunter vs. farmer theory is applied to attention-deficit hyperactivity disorder (ADD or ADHD) and adult attention-deficit disorder (AADD). The theory was first proposed by Thom Hartmann, who worked with children with ADD. The premise is that ADD attributes in only some humans may be a result of a form of adaptive behavior. Under this theory, the attributes of a hunter gave way to those of a farmer for most people as civilized society evolved from a nomadic existence to one of more permanent settlements. Over many years, most humans changed genetically, but some (those with ADD) still have the older hunter characteristics.

Overview
Hartmann notes that most or all humans were nomadic hunter gatherers for hundreds of thousands of years, but that this standard gradually changed as agriculture developed in most societies, and more people worldwide became farmers. Over many years, most humans adapted to farming cultures, but Hartmann speculates that people with ADHD retained some of the older hunter characteristics.

A key component of the hypothesis is that the proposed "hyperfocus" aspect of ADHD is a gift or benefit. The hypothesis also explains the distractibility factor in ADHD individuals and their short attention span, along with various other characteristics, such as apathy towards social norms, poor planning and organizing ability, distorted sense of time, impatience, and impulsiveness. It is argued that in the hunter-gatherer cultures that preceded farming societies, hunters needed hyperfocus more than gatherers.

While the cause(s) of ADD/ADHD in humans are not known, and continue to be the subject of considerable research. Thom Hartmann's work has also pointed to the hyperfocus aspect of ADD as a gift for many persons, a position shared by many other medical and counseling professionals.

In the hunter-gatherer cultures that preceded farming societies, hunters (presumably mostly men) probably needed hyperfocus more than gatherers (presumably mostly women). This may be connected with the fact that ADHD is diagnosed in twice as many boys as girls. It should also be noted that this gender imbalance in diagnosis is reducing as it becomes increasingly recognised by professionals that the presentation of ADHD symptoms often differs in girls and boys.

It should be understood that this hypothesis is only one of several that attempt to account for the origins of ADHD. A major competitor, probably more widely accepted, is that ADHD is merely the co-occurrence of several genetic variants. Harpending and Cochran offer a 3-phase view of history that includes hunter-gathering, female farming, and then intensive agriculture; they suggest that ADHD increased reproductive fitness in the second phase. An important view, with considerable genetic backing, is that some of these genetic variants may have value in certain kinds of social groups, such as those that have migrated.

Scientific concern around Hunter vs. Farmer theory revolves around the mismatch between the behaviours symptomatic of ADHD, and those described as being adaptive for hunters, which better fit a diagnosis of hypomania. As a theory of evolutionary psychology it is also open to the core criticisms of that discipline. That is, it is not easy to see how the theory is falsifiable, because we have no way of knowing whether ADHD-type behaviours were helpful in a hunting context. Further critics of evolutionary psychology point out that we know relatively little about the evolutionary context in which ADHD may (or may not) have evolved.

Science and the hunter vs. farmer hypothesis
The hunter vs. farmer hypothesis proposes that the high frequency of ADHD in contemporary settings "represents otherwise normal behavioral strategies that become maladaptive in such evolutionarily novel environments as the formal school classroom." An important view, with considerable genetic backing, is that some of these genetic variants may have value in certain kinds of social groups, such as those that have migrated. Genetic variants conferring susceptibility to ADHD are very frequent—implying that the trait had provided selective advantage in the past.

A 2008 New Scientist article by Tim Callaway reports that research of ADHD and related traits in different cultures offers some support for the hunter vs. farmer hypothesis. According to evolutionary anthropologist Ben Campbell of the University of Wisconsin–Madison, studies of the Ariaal, an isolated nomadic group in Kenya, suggest that hyperactivity and impulsivity—key traits of ADHD—have distinct advantages to nomadic peoples. Additionally, nomadic Ariaal have high rates of a genetic mutation linked to ADHD, while more settled Ariaal populations have lower rates of this mutation. Henry Harpending of the University of Utah reports that with this genetic mutation, "You probably do better in a context of aggressive competition."

Books
Hartmann, Thom, Attention Deficit Disorder: A New Perspective