Physiological Reactivity to Sensory Stimulation as a Measure of Personality
6 introverts and 6 extraverts were tested with respect to the increment of salivary activity as a consequence of (a) putting 4 drops of lemon juice on their tongues and (b) having them swallow 4 drops of lemon juice. Under condition (a) introverts salivated significantly more than extraverts; under condition (b) extraverts salivated significantly more than introverts. Pavlov's theory of transmarginal inhibition was suggested as a possible explanation of this reversal.