The hunter versus farmer hypothesis is a proposed explanation of the nature of

attention-deficit hyperactivity disorder Attention deficit hyperactivity disorder (ADHD) is a neurodevelopmental disorder characterised by excessive amounts of inattention, hyperactivity, and impulsivity that are pervasive, impairing in multiple contexts, and otherwise age-inap ...

(ADHD) first suggested by radio host

Thom Hartmann Thomas Carl Hartmann (born May 7, 1951) is an American radio personality, author, former psychotherapist, businessman, and progressive political commentator. Hartmann has been hosting a nationally syndicated radio show, ''The Thom Hartmann Pro ...

in his book ''Attention Deficit Disorder: A Different Perception''. This hypothesis proposes that ADHD represents a lack of adaptation of members of

hunter-gatherer A traditional hunter-gatherer or forager is a human living an ancestrally derived lifestyle in which most or all food is obtained by foraging, that is, by gathering food from local sources, especially edible wild plants but also insects, fungi, ...

societies to their transformation into

farming Agriculture or farming is the practice of cultivating plants and livestock. Agriculture was the key development in the rise of sedentary human civilization, whereby farming of domesticated species created food surpluses that enabled people to ...

societies. Hartmann developed the idea first as a

mental model A mental model is an explanation of someone's thought process about how something works in the real world. It is a representation of the surrounding world, the relationships between its various parts and a person's intuitive perception about thei ...

after his own son was diagnosed with ADHD, stating, "It's not hard science, and was never intended to be." A key component of the hypothesis is that the proposed "

hyperfocus Hyperfocus is an intense form of mental concentration or visualization that focuses consciousness on a subject, topic, or task. In some individuals, various subjects or topics may also include daydreams, concepts, fiction, the imagination, and ...

" aspect of ADHD is a gift or benefit under appropriate circumstances. The hypothesis also explains the distractibility factor in ADHD individuals and their short attention span for subject matter that does not interest the individual (which may or may not trigger hyperfocus), along with various other characteristics such as difficulty adhering to social norms, poor planning and organizing ability, distorted sense of time, impatience, attraction to variety or novelty or excitement, and impulsiveness. It is argued that in the

cultures that preceded

societies, hunters needed hyperfocus more than gatherers.

Hypothesis claims

The hunter versus 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." One example such as migration in the hunter-gatherer society, is that some of these hunter-gatherers that naturally predisposed to these various amounts of this same gene may have value in certain kinds or qualities of

social group In the social sciences, a social group can be defined as two or more people who interact with one another, share similar characteristics, and collectively have a sense of unity. Regardless, social groups come in a myriad of sizes and varieties ...

s. It was also stated that the lack of 'hyperfocus' should not be the only dichotomy of 'Farmers versus Hunter-gatherers' that was identified in Hartman's theory. Hartmann claims that most or all humans were

nomad A nomad is a member of a community without fixed habitation who regularly moves to and from the same areas. Such groups include hunter-gatherers, pastoral nomads (owning livestock), tinkers and trader nomads. In the twentieth century, the popu ...

s for hundreds of thousands of years, but that this standard gradually changed as

agriculture Agriculture or farming is the practice of cultivating plants and livestock. Agriculture was the key development in the rise of sedentary human civilization, whereby farming of domesticated species created food surpluses that enabled people to ...

developed in most societies, and more people worldwide became

farmer A farmer is a person engaged in agriculture, raising living organisms for food or raw materials. The term usually applies to people who do some combination of raising field crops, orchards, vineyards, poultry, or other livestock. A farmer mig ...

s. Over many years, most humans adapted to farming cultures, but Hartmann speculates that people with ADHD retained some of the older hunter characteristics.

Scientific basis

Hyperfocus

From an evolutionary viewpoint, "hyperfocus" was advantageous, conferring superb hunting skills and a prompt response to predators. Also,

hominin The Hominini form a taxonomic tribe of the subfamily Homininae ("hominines"). Hominini includes the extant genera ''Homo'' (humans) and '' Pan'' (chimpanzees and bonobos) and in standard usage excludes the genus ''Gorilla'' (gorillas). The t ...

s have been hunter gatherers throughout 90% of human history from the beginning, before evolutionary changes, fire-making, and countless breakthroughs in stone-age societies. Humans devised better innovations and organizational structures to boost their living and the need for hyperactivity slowly diminished over a long period of time regardless of whether they were in a gathering or farming society. K. H. Ko further states that the decreased need for 'hyperfocus' was building the conditions favourable for human language. Glickman & Dodd (1998) found that adults with self-reported ADHD scored higher than other adults on self-reported ability to hyper-focus on "urgent tasks", such as last-minute projects or preparations. Adults in the ADHD group were uniquely able to postpone eating, sleeping and other personal needs and stay absorbed in the "urgent task" for an extended time.

Positive/negative gene selection

Genetic variants (such as DRD4 7R allele) conferring susceptibility to

ADHD Attention deficit hyperactivity disorder (ADHD) is a neurodevelopmental disorder characterised by excessive amounts of inattention, hyperactivity, and impulsivity that are pervasive, impairing in multiple contexts, and otherwise age-inapp ...

are very frequent — implying that the trait had provided selective advantage in the past. However, "it is unlikely that the observed bias towards nonsynonymous amino-acid changes has been achieved only by positive selection favoring the DRD4 7R allele because the bias can be found not only in VNTR motifs of the DRD4 7R allele but also in those of the other alleles", observed by more recent research — the DRD4 7R allele had no evidence for recent positive selection. Furthermore, a recent 2020 study found that ADHD allele frequency has been decreasing for up to 35,000 years, indicating negative selection. These conclusions however, are still compatible with the theory: "Overall, our results are compatible with the mismatch theory for ADHD but suggest a much older time frame for the evolution of ADHD-associated alleles compared to previous hypotheses."

Frequency of ADHD in nomadic tribes

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 versus farmer hypothesis. According to evolutionary anthropologist Ben Campbell of the

University of Wisconsin–Milwaukee The University of Wisconsin–Milwaukee (UW–Milwaukee, UWM, or Milwaukee) is a public urban research university in Milwaukee, Wisconsin. It is the largest university in the Milwaukee metropolitan area and a member of the University of Wiscons ...

, studies of the

Ariaal The Ariaal are northern Kenyan pastoralists. They claim descent from cattle-owning Samburu who captured significant herds of camels and learned how to manage them from their eastern neighbours, the Rendille. This led them to adopt the Rendille ...

, an isolated nomadic group in

Kenya ) , national_anthem = "Ee Mungu Nguvu Yetu"() , image_map = , map_caption = , image_map2 = , capital = Nairobi , coordinates = , largest_city = Nairobi , ...

, 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 Henry Cosad Harpending (January 13, 1944 – April 3, 2016) was an American anthropologist and writer. He was a distinguished professor at the University of Utah, and formerly taught at Penn State and the University of New Mexico. He was a membe ...

of the

University of Utah The University of Utah (U of U, UofU, or simply The U) is a public research university in Salt Lake City, Utah. It is the flagship institution of the Utah System of Higher Education. The university was established in 1850 as the University of De ...

reports that with this genetic mutation, "You probably do better in a context of aggressive competition." A genetic variant associated with ADHD has been found at higher frequency in more nomadic populations and those with more of a history of migration. Consistent with this the health status of nomadic

men was higher if they had the ADHD associated genetic variant (7R alleles), whereas in recently sedentary (non-nomadic)

those with 7R alleles seemed to have slightly worse health.

References

Sources

*Hartmann, Thom, ''Attention Deficit Disorder: A Different Perception''

External links

National Mental Health association, AADD webspageArticle on Hunter Farmer Theory"What is a Hunter-type?" Article"Genomic analysis of the natural history of attention-deficit/hyperactivity disorder using Neanderthal and ancient ''Homo sapiens'' samples" Article

"The evolution of hyperactivity, impulsivity and cognitive diversity" Article
{{Attention-deficit hyperactivity disorder Attention deficit hyperactivity disorder Evolutionary psychology