The Evolutionary Role of ADHD in Prehistoric Humans: A Trait Adapted to Foraging, Now Misaligned with Modern Life

Anthropology.net

ADHD (Attention Deficit Hyperactivity Disorder) is often viewed as a modern-day challenge, marked by distractability and impulsivity that makes it difficult to navigate the structured demands of contemporary life. However, emerging research1 suggests that this trait may have been a significant evolutionary advantage in prehistoric times, particularly in hunter-gatherer societies. This perspective not only re-contextualizes ADHD as a potential evolutionary asset but also offers new insights into how people with ADHD can better adapt to the modern world.

The Prehistoric Advantage of ADHD Traits

For most of human history, Homo sapiens lived as hunter-gatherers. Fossil evidence indicates that our species has existed in this mode of life for at least 288,000 years, which accounts for approximately 95% of our evolutionary history. During this time, the ability to rapidly shift focus, seek new stimuli, and make quick decisions could have been highly advantageous.

Annie Swanepoel, a child and adolescent clinical psychiatrist, explained,

“95 percent of our evolutionary history was spent living as hunter-gatherers. That means there’s an evolutionary mismatch.”

This mismatch refers to the difference between the environments in which humans evolved and the vastly different environments of the modern world. In prehistoric societies, individuals with traits associated with ADHD—such as impulsivity, hyperactivity, and distractability—may have played crucial roles in the survival of their communities.

For example, individuals with ADHD might have excelled in foraging tasks, where their propensity to explore new areas and quickly abandon unproductive ones would have helped them locate food resources more efficiently. This trait could also have been beneficial in hunting scenarios, where impulsivity and quick reflexes were necessary for capturing prey.

The Neolithic Revolution and the Shift in Human Societies

The advent of the Neolithic Revolution around 12,000 years ago marked a significant turning point in human history. With the development of agriculture, humans transitioned from a nomadic lifestyle to one of settled farming communities. This shift led to the rise of complex societies, where individuals were expected to specialize in specific roles within a larger system.

Yuvaal Harari, in his book Sapiens, describes the agricultural revolution as a paradigm shift that forever changed the course of human society. Agriculture allowed for the establishment of permanent settlements, the growth of cities, and the development of complex social structures. However, this new way of life also placed different demands on individuals. Instead of the varied and dynamic tasks associated with hunting and foraging, people were now required to focus on repetitive and monotonous tasks, such as farming, tool-making, and other specialized trades.

This transition may have created challenges for individuals with ADHD traits, as the structured and repetitive nature of agricultural and industrial societies was less suited to their strengths. As a result, what was once an adaptive trait in a foraging context became a potential disadvantage in a more structured and sedentary environment.

Testing the Foraging Hypothesis in Modern Experiments

Recent research has tested the hypothesis that ADHD traits could have been advantageous in foraging contexts. David Barack and his collaborators designed an experiment that mimicked a foraging scenario, allowing participants to collect as many "berries" as possible in a limited amount of time by moving their cursor between virtual bushes. The challenge was to decide when to move to a new bush, as each bush yielded fewer berries the longer a participant stayed. Barack explained,

“The reason we chose that paradigm is it mimics an enormous range of decision contexts. In particular, ones that were present in our selective environment.”

The results were surprising. Participants who self-reported ADHD symptoms performed better than their non-ADHD counterparts. They were more adept at determining when to move on to a new bush, thus maximizing their berry yields. This finding supports the idea that individuals with ADHD traits may have excelled in foraging tasks, providing a tangible link between these traits and survival in prehistoric environments.

The Implications for Modern Life

While these findings offer a compelling evolutionary explanation for ADHD, they also raise important questions about how individuals with ADHD can adapt to the demands of modern life. Today’s world, with its emphasis on long periods of focused attention, complex decision-making, and a plethora of choices, can be overwhelming for those with ADHD.

Barack suggests that understanding the types of decisions in which people with ADHD excel can help in designing environments that play to their strengths. For example, simplifying decision-making processes—such as reducing the number of choices available at any given time—could help individuals with ADHD make better decisions. He noted,

“The classic example here is when you’re at the grocery store and there’s just overwhelming amounts of choices. The alternative environment would be getting single offers at a time… Do you want this? Do you not want this?”

An Evolutionary Perspective on ADHD Treatment

While the evolutionary perspective provides a valuable framework for understanding ADHD, it also suggests that modern treatments should be multifaceted. Swanepoel emphasized that,

“It’s not a pathology in the child as much as it’s the mismatch between the child and what their environment is like.”

This perspective encourages a balanced approach to treatment, one that includes both pharmaceutical interventions and environmental modifications.

Swanepoel shared a relevant case from her practice involving a teenager with severe ADHD. Initially, medication helped the teenager manage schoolwork. However, after joining a college soccer team and engaging in regular intense physical activity, the teenager was able to stop taking the medication while maintaining good academic performance. Swanepoel said,

“You have two options. One is to change the child, through medication, for example. The other is to change the environment.”

Conclusion

The evolutionary history of ADHD highlights the complexity of human adaptation. Traits that were once advantageous in the dynamic and varied environments of prehistoric societies may now pose challenges in the structured and repetitive contexts of modern life. By understanding ADHD through an evolutionary lens, researchers and clinicians can develop more effective strategies for helping individuals with ADHD thrive in today’s world. This approach not only re-frames ADHD as a potential evolutionary asset but also underscores the importance of creating environments that align with our ancestral strengths.

1

Barack, D. L., Ludwig, V. U., Parodi, F., Ahmed, N., Brannon, E. M., Ramakrishnan, A., & Platt, M. L. (2024). Attention deficits linked with proclivity to explore while foraging. Proceedings. Biological Sciences, 291(2017). https://doi.org/10.1098/rspb.2022.2584