A broad theory, not necessarily in conflict with the current medical research findings, is the hunter vs. farmer theory, first presented by Thom Hartmann, which holds that in some ways, some ADD attributes in some humans may be a form of adaptive behavior developed over a long period to match the environment. In easier terms, the change was refinement of skills to suit changing needs. Under the theory, as civilized society evolved, the attributes of a hunter gave way to those of a farmer for most people as the survival skills needed changed.

Hartmann takes an approach from biological evolution to argue that ADHD is not a disorder, but an expression of biodiversity. In his book ADD - Attention Deficit Disorder (1997), Hartmann developed the idea that people having ADHD symptoms may have simply inherited a collection of genes that were selected for the time when hunting was particularly important. From an evolutionary point of view, it is quite acceptable that humans—like other animals—differ in their biology and pass on their traits from generation to generation. This idea is the basis of another of his works, The Edison Gene: ADHD and the Gift of the Hunter Child (2003).

Hence the idea that thinking in terms of attentional 'differences' rather than attentional 'disorders' may be helpful, by helping focus energy towards the individual's strengths and uniqueness.

ADD/ADHD a hoax?
There are some claims that ADD/ADHD is simply a hoax. Many of these charges are that there has been a conspiracy between medical and counseling professionals and the pharmaceutical companies, or that the former have been misled by the latter, which have profited greatly from the sale of medication such as Ritalin and Adderall, and have advertised their products extensively. Since medications became available, there has been an increased number of persons diagnosed. This might be explained by increased awareness or easy solution for doctors.

However, the results achieved in clinical tests with such medication and anecdotal evidence of parents, teachers, and both child and adult sufferers has proved there is both a condition and successful treatment options for most people who meet the criteria for a diagnosis.

A further problem is that ADD and ADHD are syndromes, associations of symptoms. There is no well established cause for the condition. This means that it may actually be a blanket term covering a multitude of conditions with a variety of causes.

Confusion may also arise from the fact ADD/ADHD symptoms vary with each individual, and some mimic those of other causes. A known fact is that, as the body (and brain) matures and grows, the symptoms and adaptability of the individual also change. Many individuals diagnosed with ADD/ADHD successfully develop coping skills, while others never do.