Salivary Response to Lemon Juice as a Measure of Introversion

Abstract

50 men and 50 women were administered the EPI and tested with respect to the increment in salivation produced by putting 4 drops of pure lemon juice on the tongue for 20 sec. It was found that in both groups introversion correlated approximately 0.7 with increase in salivation; there was no correlation with neuroticism. When a commercial product was substituted for pure lemon juice, all correlations became insignificant, possibly due to the weaker concentration of the product. The results are explained (and were predicted) in terms of an hypothesis relating introversion to cortical arousal.