Social Enhancement and Impairment of Performance in the Cockroach.
Zajonc, Robert B., Alexander Heingartner, and Edward M. Herman.
Journal of Personality and Social Psychology 13.2 (1969): 83-92.
http://psycnet.apa.org/index.cfm?fa=buy.optionToBuy&id=1970-00434-001
ゴキブリでも単純な他者の存在で個々の行動が影響を受ける，，，というもの。
大元は
Triplett, N. (1898)
The dynamogenic factors in pacemaking and competition.
Journal of Psychology, 9, 507-533.
http://www.jstor.org/stable/1412188?origin=crossref
下記に解説有り。ありがたや。
http://psychclassics.yorku.ca/Triplett/
