A new study has demonstrated that a bunch of the important brain processes known as 'executive functions' aren't affected by someone's sex or gender, as it has been argued before.
The research references more than 150 previous studies into executive functions and associated behaviour, finding "small and subtle to no sex and gender differences in executive function".
These executive functions are brain processes covering things like attention, reasoning, working memory, decision making, impulse control, and problem solving.
However, the researchers do point to executive function differences related to our genotype, how we develop as we grow and mature, and neural circuit mechanisms – all of which are highlighted as worthy of further study.
"Overall, we find little support for significant gender or sex differences in executive function," write the researchers, Nicola Grissom from the University of Minnesota, and Teresa Reyes from the University of Cincinnati.
As a whole, executive functions affect our ability to handle events happening around us and to plan for future events; to a large extent, they determine how we behave and how we interact with the world.
If well-developed, these skills can lead to success socially, academically, and professionally, the researchers note. If under-developed or disrupted, health issues like attention-deficit hyperactivity disorder (ADHD) and schizophrenia can appear.
And part of the reason for the new research was to look into those mental health issues: risk, rates of progression, and the severity of the conditions vary between sex and gender. Men are more likely to develop schizophrenia at a younger age than women, for example, while ADHD is more common in boys than in girls.
So, is there a difference in executive functioning related to sex and gender that explains these variations? Not according to this study, which analysed multiple previous studies on attention, impulsive action, decision making, and working memory – studies covering both humans and animals.
"It would be incorrect to conclude that gender and sex is the primary factor driving individual differences in executive function and cognitive performance," explain the researchers, having worked through the available data.
What discrepancies there are probably have other root causes, Grissom and Reyes say. They note previous research showing that executive functioning can be affected by a whole host of environmental pressures that happen to us as we grow up, everything from problems in the womb to insults in the playground.
These "developmental trajectories", as the researchers call them, are also likely to be responsible for differences in our cognitive thinking and behaviour (as well as our risk of mental health issues) – not any built-in differences caused by sex or gender.
The researchers also suggest that each sex and gender may attempt different tasks and challenges differently – and those variations may explain some of the variations in performance in some of the studies. In a memory task, for example, different neural activity was noted between adolescent girls and boys.
"The sex differences in strategy suggest that different circuit and/or molecular mechanisms are utilised by males and females to solve the same cognitive problems," explain the researchers.
"This means that even though ability may be the same, the strategies employed are unlikely to be supported by the same neurobiological mechanisms."
All of this matters not just to show we all have the same capacity for higher thinking, but also to find better ways of working out how executive functioning can be impaired – and how we can treat conditions where that's the case.
It's possible that the stresses of life, from drug abuse to head injuries, affect different sexes and genders differently, say the researchers, and knowing more about that could help us lower the risk of mental health problems further down the line.
"It is critical that females and males of all species continue to be examined, to determine the mechanisms supporting executive function across genders and sexes," conclude the researchers in their paper.
"Indeed, this work may identify alternative pathways that can be harnessed and enhanced in patients with disorders associated with executive function deficits."
The research has been published in Neuropsychopharmacology.