Who is better at multi-tasking, men or women?

This week's post has been fairly hard for me to write; largely because the article brings up more questions for me than answers. The topic is multitasking. Multitasking in psychology is defined as simultaneously engaging in two mental or physical activities at once. Like most people, I am constantly multitasking but have given very little thought to whether I am actually skilled at multitasking. What might that even mean? And if it is the case that some people multitask better than others, are those people more likely to be men or women? Recently, Timo Mäntylä of Stockholm University published his findings from exactly this question: 

Who is better at multi-tasking, men or women?

To do this, Dr. Mäntylä conducted two experiments. First, he had 72 adults (36 men) simultaneously do two computer tasks: the counter task and the n-back task. In the counter task, there were three clocks on the screen and the participants were instructed to hit the space bar when the counters read a target time (e.g., multiples of 11). Thus, this task required the participant to constantly monitor the three clocks. In the n-back task, the participant saw common Swedish first names presented at 2-second intervals on the computer screen. Every time the name on the screen was the same as the name presented 4 trials ago, the participant was to press a key. Thus, the participant needed to hold the last 4 names presented in mind in order to perform well on the task. Multitasking success was measured by correct responses in both tasks. Dr. Mäntylä and his colleagues found that men significantly outperformed women. 

                                         

Men outperforming women in this multitasking paradigm was then related to spatial reasoning ability. Spatial reasoning in psychology is a mental skill where an individual can manipulate mental representations accurately. To measure this ability, participants are often shown images of geometric shapes or impossible objects, the image is removed, then the participant is asked to mentally rotate the object a number of different ways, and finally is asked to correctly identify the image corresponding to their new mental representation. Spatial reasoning ability is thought to be related to abilities such as navigating, design, and construction. In previous studies, psychologists have found that men have superior spatial reasoning to women, with only one exception. These differences don't exist when women are in the menstrual phase of their reproductive cycle. 

Given this background, Dr. Mäntylä conducted a follow-up study to see whether the differences he observed between men and women in multitasking were related to spatial reasoning. To do this, he has 88 participants (40 men) complete a spatial reasoning test, the same multitasking activities from Study 1, and collected information about menstrual phase for the women. Again, men outperformed women in the multitasking activities, but with very interesting mechanistic insight. In this study he found that spatial reasoning ability accounts for the differences in multitasking performance between men and women, and the differences were not observed between men and women in their menstrual phase. 

I realize this got complicated very quickly, and for me I'm left with an unsatisfied sense on confusion about what these findings mean. The most obvious question, why would spatial reasoning be better for women during menstruation? I would love thoughts from my colleagues in biology about this. Could it be that during the luteal phase--when fertility is at its peak--mental energy is needed elsewhere, or perhaps that spatial reasoning skills are bolstered during the menstrual phase for survival? The biggest question I am still grappling with is whether this lab study is ecologically valid. Ecological validity describes how well the tasks in the lab approximate the conditions of the real world. To be honest, these tasks don't come close to what I think of as multitasking skills. Instead, I think of my best friend who used to paint her toenails at red lights while driving her manual car through Southern California traffic, while my fiancé is often so deep in thought about his work that he can't attend to where on earth his glasses or keys are. 

                                          

In a more practical way, this study has forced me to think a lot about multitasking from many different perspectives; as a psychologist, as a woman, as a professional. Some people must multitask because there are simply too many demands on their time. Some salient examples are working mothers and emergency room physicians. This finding suggests that making a concerted effort to practice and improve spatial reasoning skills may increase your ability to complete multiple mental tasks simultaneously. More broadly, I have spent a lot of time thinking about whether multitasking well is always a good thing. Rather than trying to increase our abilities to divide our attention between mental tasks, should we instead get better at refusing tasks which divert our attention unnecessarily? 

Mäntylä, T. (2013). Gender Differences in Multitasking Reflect Spatial Ability.Psychological Science.