Facial and vocal cues of deception and honesty

Facial expressions and vocal cues (filtered speech) of honest and deceptive messages were examined in posed and spontaneous situations. The question of interest was the degree to which nonverbal cues transmit information about deception. Results indicated that (a) for both the facial and vocal channels, posing (as compared to spontaneous behavior) produced a higher level of communication accuracy; (b) facial expressions of deceptive (as compared to honest) messages were rated as less pleasant, while vocal expressions of deception were rated as less honest, less assertive, and less dominant, particularly in the posed condition; (c) the sender's ability to convey honesty was negatively correlated with his/her ability to convey deception, suggesting the existence of a demeanor bias—individual senders tend to appear and sound consistently honest (or dishonest) regardless of whether they deliver an honest or a deceptive message; (d) in the posing condition, the sender's abilities to convey honesty/deception via facial and vocal cues were positively and significantly correlated, whereas in the spontaneous condition they were not; and (e) senders whose full (unfiltered) speech indicated more involvement with their responses were judged as more honest from both their vocal (filtered speech) and facial cues, in both the honest and deceptive conditions.     

Group participation and intergroup relations: An experimental study of negotiation groups

Negotiations were conducted to investigate the effects on settlement-points andon the attitudes and perceptions of participants of (i) group participation and (ii)belief in own group's point of view, in a 2 × 2 factorial design. Ninety-six school children prepared cases in groups of four before representing their group's position against an individual of a similarly prepared opposed group. Group participation was manipulated by groups either participating in preparatory discussions or observing video films of another group's discussions. Belief was manipulated by systematically varying the composition of groups according to scores on a pre-test of attitudes towards the raising of the school-leaving age. In general the belief manipulation operated as expected, ‘believers’ exhibiting less variability, more tit-for-tat agreements and less opinion change than the ‘disbelievers’. Group participation did not influence the measures as predicted, and measures of interpersonal perception did not conform to the pattern of findings in recent experiments on intergroup discrimination. The results are discussed in terms of (i) their relevance to the issue of the appropriate relationship of the representative to his group in a negotiation and (ii) their implications for intergroup relations theory.     

Lump detection in simulated human breasts

Sixteen observers palpated silicone models of human breasts containing lumps 1.6-12.1 mm in diameter. Detectability depended on the size of the lump, producing a systematic psychometric function. In eight observers who participated in three or more sessions, performance improved with practice, with most improvement occurring within one or two 26-trial sessions. Three-week retention measures disclosed no appreciable decrease in performance, but a significant correlation was found between the number of lumps detected and duration of trial (p < .01). There was no difference in performance between four observers who used their preferred hands and four observers who used their nonpreferred hands. These data establish that examination of breast models for the detection of lumps simulating cancer is a task amenable to experimental analysis.