The theory of false alarm for laughter could explain the involuntary laugh when someone is tickled. To put this hypothesis to the test, we handed out a questionnaire (180 items) with two hundred university students. Our main results are:In women who like being tickled, we discover components related to pleasure, erotism, feeling of affection, arousal, uncontrollability, domination, sexism and Darwinian (golden ratio) and psychological traits (empathy, low schizotypy and external locus of control) that are not present in the laughter at a stumble. The relation of both types of laughter with sense of humor is also differential. In men who like being tickled, we discover components related to masturbation, sexual fantasies, erotism, arousal, domination, sexist humour and Darwinian (square chin, feeling of masculinity) and psychological traits (empathic stress, low schizotypy, external locus of control and overall self-esteem). The relationship between being tickled and self-esteem shows a double aspect in men: It is positive in men who like being tickled and negative in men who do not like being tickled. For women there is not a relationship between self-esteem and tickling. Our conclusion is that laughter of ticklishness is a Darwinian feature related to empathy.
M. Davila Ross, M. Owren and E. Zimmermann, “The Evolution of Laughter in Great Apes and Humans,” Communicative and Integrative Biology, Vol. 3, No. 2, 2010, pp. 191-194.
T. Singer, “The Neuronal Basis and Ontogeny of Empathy and Mind Reading: Review of Literature and Implications for Future Research,” Neuroscience and Bio-behavioral Reviews, Vol. 30, No. 6, 2006, pp. 855-865.
N. C. Stefanis, M. Hanssen, N. K. Smirnis, D. A. Avramopoulos, I. Evdokimidis, C. N. Stefanis, et al., “Evidence That Three Dimensions of Psychosis Have a Distribution in the General Population,” Psychological Medicine, Vol. 32, No. 2, 2002, pp. 347-358.
J. B. Rotter, “Generalized Expectancies for Internal versus External Control of Reinforcement”, Psychological Monographs: General and Applied, Vol. 80, No. 1, 1966, pp. 1-28. http://dx.doi.org/10.1037/h0092976
B. Campbell, E. Schellenberg and C. Y. Senn, “Evaluating Measure of Contemporary Sexism,” Psychology of Women Quarterly, Vol. 21, No. 1, 1997, pp. 89-102.
A. A. Bailey and P. L. Huud, “Finger Length Ratio (2D: 4D) Correlates with Physical Aggression in Men But Not in Women,” Biological Psychology, Vol. 68, No. 3, 2005, pp. 215-222.