Weekly Roundup: Smiling and Seeing Happiness, Men and Women's Brains, Sleep and Memory, Smelling Your Way to Better Health

Weekly roundup of fascinating research into the brain and mind

As usual it is always a strain to decide on which research to report on with so much being published - let’s stick this week with themes I’ve reported on previously and let’s start with happy stuff:

Smiling

There was a legendary study conducted many years ago (in 1988 by Fritz Strack to be precise) that seemed to prove that involuntary smiling seemed to improve mood (or finding cartoons funnier - again to be precise). This was a big thing at the time seemingly proving that body and brain are more interconnected than most had assumed at that time. Indeed this was an amazing proposition and lapped up by students of psychology, and others, the world over.

However, over the years many of these classic psychological experiments have failed to be replicated - this is the so-called replication crises. This includes that classic experiment which was subject to a large-scale replication of said smiling experiment - with disappointing results.

However, one of the insights that the replication crises has given us is that it can be difficult to measure psychological constructs because so many things can be happening at the same time that influence the outcome. For example, in the above experiments it was found that whether a participant knew they were being filmed influenced their responses.

Anyhow not to go too far off on a tangent - a recent piece caught my eye because it is related to the above smiling experiments but in a different way. Rather than looking at one’s own mood and whether smiling can influence this, it looked at smiling and judging happiness in others. A nice twist and with modern technology and methods also easier to measure.

So how did Themis Efthimiou et al. of the University of Essex do this?

In a first they used electrical stimulation to electrically stimulate the facial muscles responsible for smiling and because of the nature of this they could control the timing and length of the “smiles” precisely. Intriguing.

47 participants took part in this study and they were wired up and were asked to judge the happiness levels of faces that they then observed. These faces had already been categorised as happy or sad (or ambiguous). And you may be intrigued - did this really affect their perceptions?

Yes, it did, even an electronically stimulated “smile” lasting only 500 milliseconds was enough to shift perception of ambiguous or neutral facial expressions and judge them as more happy.

So, smiling will make you see the world as a little happier - even if that smile is involuntary. Only a little bit happier but happier nonetheless!

Men and women’s brains

I did an in-depth review of women’s and men’s brains in 2022 to try to get to grips with the conflicting evidence of whether there are really any differences between men’s and women’s brains. My conclusion is that there are, but this is not in any obvious structures, rather in gene expression and response patterns of neurons and regions.