These two ideas – the role of arousal on our willingness to cheat, and neural adaptation – are connected because the brain does not just adapt to things such as sounds and smells. The brain also adapts to emotions. For example, when presented with aversive pictures (eg, threatening faces) or receiving something unpleasant (eg, an electric shock), the brain will initially generate strong responses in regions associated with emotional processing. But when these experiences are repeated over time, the emotional responses diminish.
In our study, we went one step further. Might the brain also adapt to behaviour of our own making that we find aversive? In other words, if we engage in behaviour we feel bad about over and over again, does our emotional response to this behaviour adapt? If so, then we’ve got a prediction: since we know that emotional responses can constrain our willingness to be dishonest, if these responses decrease through adaptation, dishonesty ought to increase as a result.
To test this, we needed to run an experiment that did two things. We needed a task that encouraged individuals to be dishonest on a repeated basis. And we needed to gauge how individuals’ emotional arousal levels changed as opportunities to be dishonest repeated themselves.
We had participants lie in an fMRI scanner and send messages to a second person, who sat outside the scanner, by entering keyboard responses. Participants were instructed that their responses would be relayed via connected computers. In some stages of the task, participants had repeated opportunities to make their messages dishonest in order to earn additional money. Importantly, they could be as dishonest as they wanted to – it was entirely up to them and could vary from message to message. This allowed us to see if the messages were equally dishonest, or if there was a change in people’s willingness to be dishonest over time. Meanwhile, the fMRI data allowed us to examine how emotional arousal levels changed as dishonest messages were sent. We did this by examining the amygdalae, two almond-like regions embedded deep within the brain that respond to negative emotions such as fear and threat.
To begin with, participants were often only a little dishonest, though these small trespasses were accompanied by strong responses in the emotion-processing network. But over time, the participants seemed to get used to it, adapting to the adverse feeling that came with sending dishonest messages. They ceased having strong emotional responses. And eventually, the door flew open: they could be much more dishonest than at the beginning, but with increasingly limited emotional sensitivity. Dishonesty began to feel not so bad.
This study might suggest a pessimistic view of humanity, with everyone gradually becoming emotionally null to bad behaviour, more corrupt and more egotistical. But that’s not the only way to see these results. One positive message to take away is that emotion plays a crucial role in constraining dishonesty. Perhaps that means a solution to dishonesty is available: strong emotional responses in situations where dishonesty is a temptation could be reinstated so as to reduce one’s susceptibility to it. In fact, a recent study achieved this by having a group of participants believe that their hearts were pounding quickly when they faced the temptation to be dishonest. This group cheated less than an alternative group of participants who were made to believe that their heartbeats were calm and steady.
There have also been a number of behavioural interventions proposed to curb unethical behaviour. These include using cues that emphasise morality and encouraging self-engagement. We don’t currently know the underlying neural mechanisms that can account for the positive behavioural changes these interventions drive. But an intriguing possibility is that they operate in part by shifting up our emotional reaction to situations in which dishonesty is an option, in turn helping us to resist the temptation to which we have become less resistant over time.
This article was originally published at Aeon and has been republished under Creative Commons.