Peripersonal Space (PPS) is the space surrounding the body that the brain is super-committed to keep track of. The brain produces privileged responses when something enters our PPS that can potentially harm the body. Even other sapiens can become noxious when they enter our PPS (just ask Philip Jacobs). Peripersonal space can expand to wrap around the tools we use or contract when we are immobilized.
PPS size shows individual variation and changes with social context. Testosterone is also known to modulate social interactions. A study by Catherine Masson et al. looked at how administering testosterone to women altered their Peripersonal Space in the presence of another individual. Researchers used a visuotactile interaction task to measure changes in PPS of participants after administration of testosterone or placebo (N=19).
Women who were given testosterone unconsciously appropriated a larger space as their own. The subject’s own PPS expanded but that of an individual close to them was perceived as remaining constant. This expansion of PPS was significantly more in women who scored high in trait anxiety.
The authors opined that testosterone (a known motivator of social dominance) seems to be causing subconscious “embodied changes in sensory-motor processing”. Read more about the study by Catherine Masson, Donné van der Westhuizen, Jean-Paul Noel, Adala Prevost, Jack van Honk, Aikaterini Fotopoulou, Mark Solms & Andrea Serinox here or read preprint here.