But the guy on the left may be signalling something else. A paper soon to be published in the academic journal Psychological Science, titled "The Ergonomics of Dishonesty," says that people who take on "expansive" poses are more likely to deceive others than people who take more "restrictive" poses.
"...individuals who engaged in expansive postures were more likely to steal money, cheat on a test, and commit traffic violations in a driving simulation."
For the academically minded, here is the Abstract from that paper:
Research in environmental sciences has found that the ergonomic design of human-made environments influences thought, feeling and action. Here, we examine the impact of physical environments on dishonest behavior. Four studies tested whether certain bodily configurations—or postures—incidentally imposed by our environment lead to increases in dishonest behavior. The first three experiments found that individuals who engaged in expansive postures (either explicitly or inadvertently) were more likely to steal money, cheat on a test, and commit traffic violations in a driving simulation. Results suggested that participants’ self-reported sense of power mediated the link between postural expansiveness and dishonesty. Study 4 revealed that automobiles with more expansive driver’s seats were more likely to be illegally parked on New York City streets. Taken together, results suggest that: (1) environments that expand the body can inadvertently lead us to feel more powerful, and (2) these feelings of power can cause dishonest behavior.Of course, the real key to alpha is point (1) in the last sentence: expanding the body leads to feeling powerful, and feeling powerful makes you more attractive to women.
If you want all the details, here's a link to the full paper (in .pdf format).
The Ergonomics of Dishonesty: The Effect of Incidental Posture on Stealing, Cheating, and Traffic Violations
It appears that people who take up a lot of room without apologizing for their presence are, well, jerks. And we all know that chicks dig jerks. Therefore, taking up a lot of room is attractive to women. Go, therefore, and do likewise.