Dr Simone Schnall explains how your bodily state affects your perception
"How do we see the world? We know that in social situations people are often influenced by various irrelevant factors, such as current emotions, stereotypes, and so on. This can bias decisions and lead to suboptimal outcomes.
"But how do people see the physical environment around them? For example, how far is it to walk to a coffee shop around the corner, and then how large does the coffee cup look to you? Of course objects and distances are objectively specified: the walk might be, say, half a mile long, and the coffee cup might be four inches in diameter.
"What our research shows is that even perceiving such objective features is influenced by subjective factors, such as how you currently feel, whether you are hungry or thirsty at the moment, and so on. In other words, your bodily state can change how you perceive the world around you.
"Why is this the case? Because in a way the body tells you what to do next. For example, I might be too exhausted to trek to the coffee shop and therefore rather stay put. One the other hand, the thought of a freshly baked mince pie and an extra-large latte might feel like it's worth the little walk after all. So perception helps you perform an unconscious cost-benefit analysis on what to do next, which for the most part is highly adaptive."
Dr Simone Schnall is a Reader in Experimental Social Psychology in the Department of Psychology at the University of Cambridge, and Director of the Cambridge Body, Mind and Behaviour Laboratory. She is Director of Studies in Psychological and Behavioural Sciences at Jesus College.