- ADHD may have evolved because foragers moved when food was scarce
- Survival rates meant ADHD could evolve over the last 12,000 years
- READ MORE: What are the symptoms of ADHD?
Attention deficit hyperactivity disorder (ADHD) may not play a major role in survival in today’s society, but for hunter-gatherers it could have saved their lives.
ADHD is a neurodevelopmental disorder with symptoms that include difficulty paying attention, hyperactivity, and impulsivity.
Now, researchers at the University of Pennsylvania set out to uncover the origins of the disorder and discovered that it may have evolved at least 12,000 years ago.
The study asked hundreds of people to play a foraging video game to test how long participants searched for berries in one bush before moving on to another, the same behavior as hunter-gatherers.
The team found that people with ADHD quickly headed to new bushes after failing to find berries and believe ancient humans may have survived because they evolved to have impulsiveness to keep going when food sources were scarce.
Hunter-gatherers with ADHD may have had a better chance of surviving because they were more likely to quickly move to another area when food in the region became scarce. This may mean they had a higher survival rate, allowing ADHD to evolve over thousands of years.
“If (these traits) were truly negative, then you would think that over evolutionary time they would be selected against,” said David Barack, a philosopher and neuroscientist at the University of Pennsylvania and lead author of the study. The Guardian.
“Our findings are initial data that suggest advantages in certain election contexts.”
There are an estimated 8.7 million people with ADHD in the United States, at least six million of whom are children.
Studies on ADHD have linked genetic factors to the disorder, and some scientists are investigating brain injuries as the primary cause.
The team instructed 506 American participants to play an online foraging game for eight minutes, and during that time, they were asked to pick as many berries from a digital bush as they could.
They were given the option to move on to stay in the current bush or move to another one, and the researchers found that those with ADHD were more likely to cut their losses and move to another bush faster than participants without ADHD.
Participants were given instructions for the foraging task in the virtual patch and were asked to forage for as many berries as they could within a limited time period. Participants with ADHD spent four seconds less in a bush before moving on to the next than participants without ADHD
The researchers found that those with ADHD were more likely to cut their losses and move on to another bush faster than participants without ADHD.
The researchers asked participants to complete a questionnaire to identify those who had ADHD before playing.
They asked him questions including: “How often do you have difficulty concentrating?” and ‘How often does he leave his seat in…situations where he is expected to remain seated?’
The study, published in the real societyexplained that based on the participants’ responses, the researchers identified that 67.3 percent of the participants tested positive for ADHD.
The researchers used a machine learning algorithm that scored the self-reported assessment based on updated criteria for the disorder from the Diagnostic and Statistical Manual of the American Psychiatric Association, Fifth Edition (DSM-5).
Participants were excluded if they completed fewer than 25 trials or if they reported not understanding the instructions, bringing the final number of participants to 457.
The researchers tested links between participants’ foraging decisions and their self-reported ADHD scale scores and found that those who ranked higher on the ADHD spectrum spent four seconds less in each patch and picked more berries. than their counterparts without ADHD.
Their findings shed light on how hunter-gatherers may have survived by moving to a different area when food in one region was scarce.
Although the underlying cause of ADHD remains unknown, the disorder tends to be transmitted genetically, and family members of people with ADHD have an 80 percent chance of developing it, according to the National Library of Medicine.
“It is difficult to determine exactly how behaviors associated with ADHD may have been adaptive in past environments, and these results are compelling because they demonstrate measurable differences in the foraging strategies employed by individuals with and without ADHD,” Dan Eisenberg, co-author of the study. and associate professor at the University of Washington in Seattle said new scientist.
“ADHD can be a serious problem, but it is largely due to current environments,” he added.