How to quickly and easily feel more powerful and increase self-esteem:

In line with recent theories of embodied cognition, the authors propose that the self-concept may be embodied in sensory-motor representations. To test this notion, two studies investigated the effects of bodily feedback from a gesture associated with power (making a fist) on the self-concept. As expected, making a fist led male participants to perceive themselves as more assertive and esteemed (Study 1) and to display stronger associations between the self-concept and power (Study 2), while these effects were absent among female participants. The gender difference may reflect that men are more prone to use physical force to gain social influence. The results indicate that people’s conceptions of themselves are partly grounded in bodily experiences.

Source: “The embodied self: Making a fist enhances men’s power-related self-conceptions” from Journal of Experimental Social Psychology, Volume 45, Issue 4, July 2009, Pages 828-834