Traits such as distractibility and impulsivity, which are common in attention-deficit hyperactivity disorder (ADHD), may have given our ancestors an evolutionary advantage by improving their tactics when searching for food, researchers say. say the researchers.
ADHD is a neurodevelopmental disorder with symptoms such as impulsivity, confusion, and difficulty concentrating. Although prevalence estimates vary, the number of diagnoses is increasing in many countries, including the UK.
The researchers say that although some of these traits tend to be viewed negatively, they may have helped people find new places to forage.
The study's lead author, Dr. David Barak of the University of Pennsylvania, said the study shows why ADHD is more prevalent than expected from random genetic mutations alone, and more broadly, why inattention and impulsivity He said that this provides a potential explanation as to why such characteristics are responsible. was common.
“if [these traits] “If they were truly negative, you would think that over evolutionary time they would become unselected,” he said. “Our findings are an early data point and suggest benefits in certain selection situations.”
Writing in the journal Proceedings of the Royal Society B: Biological Sciences, Barack et al. reported how they analyzed data from 457 adults who completed an online foraging game in which they collected as many berries as possible within eight minutes. .
The number of fruits obtained from each bush decreased with the number of foraging sessions.
During the task, participants can continue collecting berries from the bushes in their original location or move to a new patch, although the latter takes more time.
The research team also screened participants for ADHD-like symptoms (although they stress this is not diagnostic), with 206 participants having positive results. found.
The researchers found that participants with higher scores on the ADHD scale spent less time in each patch of bushes than those with lower scores. In other words, they were more likely to abandon their current patch and look for a new one. Importantly, the team also found that such participants earned more points in the game than participants with lower scores on the ADHD scale.
Researchers said the results are consistent with other studies suggesting nomadic populations that benefit from exploration tend to have genes associated with ADHD. .
However, he added that the study had limitations, including that ADHD-like symptoms were based on self-reporting.
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Barack said he needed to conduct experiments with people diagnosed with ADHD and real-world foraging tasks, especially since the latter requires much more effort to move between patches than in an online game. I mentioned that there is.
Michael J. Rees, a professor of science education at University College London who was not involved in the study, said ADHD appears to be associated with serious negative effects, but he and his colleagues have He said he had argued that ADHD could be helpful in situations that require exercise. Decision making was appreciated.
“It's great to see experimental evidence from David Barak et al. that participants who score high on ADHD are actually more likely to switch their foraging activities in a way that can be characterized as impulsive.” “In the evolutionary past, such behavior may have sometimes been highly advantageous,” he says.
“ADHD can be a serious problem, but it's largely a problem caused by today's environment.”
