Back in the 70's, a classic study (PDF) showed that people using a photocopier were just as likely to give way to a line-pusher who gave the nonsense excuse "because I need to make copies", as they were to one who gave the more sensible excuse "because I'm in a rush". Ellen Langer and colleagues interpreted their finding as showing how mindless we often are. As soon as we hear the word "because", we assume the excuse that follows is justified and respond accordingly. Now Scott Key and colleagues have replicated this classic study, with the further aim of finding out if some personality types are more likely than others to give way.
Key's team were interested in two key personality factors. The first was "need for cognition", a strange-sounding term that refers to a person's tendency to engage their brain. It's measured by agreement with statements like "I find satisfaction in deliberating hard and for long hours", and it's been shown that people who score highly on this measure tend to be more resistant to persuasion. In this case, to the researchers' surprise, the factor was found to be irrelevant. Of the 129 students who were tested, the high scorers on "need for cognition" were just as likely to give way as low scorers.
The second factor was "self-monitoring", which as you'd expect describes the extent to which a person tends to keep a check on their own behaviour, especially in relation to social rules. The researchers thought that students who scored highly on this measure would be more likely to give way at the photocopier, in order not to cause a scene, but the opposite turned out to be true. High self-monitors were less likely to give way. Perhaps their concern to obtain the photocopies they'd been instructed to get trumped any worries about causing a social scene.
"We hope that our research ... spurs future research into what appears to be a neglected but important field of study: how individual differences moderate processes of behavior change," the researchers said.
M SCOTTKEY, J EDLUND, B SAGARIN, G BIZER (2009). Individual differences in susceptibility to mindlessness Personality and Individual Differences, 46 (3), 261-264 DOI: 10.1016/j.paid.2008.10.001