Here are the results of a highly unscientific survey of how tall physicists are.  The sample population is members of the phys-l@lists.nau.edu listserv who (1) personally identified as a physicist and (2) were willing to share their height.  The sample was biased towards, but not totally confined to, the United States.

Survey says...

Apparently, physicists are fairly tall.  I leave it to others with too much time on their hands to wonder what the reasons are.