Testing for the motivation impairment effect during deceptive and truthfulinteraction

According to the motivation impairment effect (MIE) hypothesis, deceivers w ho are highly motivated to succeed should suffer detrimental effects on non verbal performance but facilitative effects on verbal performance relative to deceivers who are less motivated. This should make highly motivated dece ivers' lies more detectable when receivers have access to nonverbal channel s. Burgoon (1998) articulated a number of problems with the reasoning under lying the motivation impairment hypothesis and with the data used to suppor t it. Drawing on a more recent theory of interpersonal deception, the curre nt investigation challenges the MIE hypothesis by advancing the alternative predictions that (a) motivation often enhances both verbal and nonverbal p erformance and (b) does so irrespective of whether deception or truthtellin g is occurring. Results from multiple operationalizations of motivation and performance support these predictions.