The BPS Research Digest blog (here) featured a paper by Gu, Zhong and Page-Gould, Listen to Your Heart, When False Somatic Feedback Shapes Moral Behaviour.

It seems that when we make a decision, how moral it is can be affected by our heart rate. This does not rise to consciousness.

Gu and his colleagues think that a fast heart beat is interpreted by people as a sign they are stressed and that they should adhere to moral conventions as a way to escape that stress. The new finding is consistent with Antonio Damasio’s influential Somatic Marker hypothesis, which is based on the idea that bodily feedback guides our decisions, often at a non-conscious level.

It is interesting that when consciousness seems to be involved, the affect is lessened.

… the moral decision-making of people who are more mindful (for example, they agreed with statements like: “I perceive my feelings and emotions without having to react to them”) was unaffected by the false cardiac feedback. The researchers also found that telling participants that the financial game was a “decision-making” task led to immunity from the false heart feedback, relative to being told the game was an “intuitive task”.
This last result is particularly intriguing since we usually assume that thinking more deliberatively helps rein in the wild horses of our emotions, allowing us to behave more morally. The finding of Gu’s team suggests that in some circumstances at least, thinking more deliberately can undermine the influence of the heart, actually making it less likely that we’ll make a more moral decision.

Here is the paper’s abstract:

A pounding heart is a common symptom people experience when confronting moral dilemmas. The authors conducted 4 experiments using a false feedback paradigm to explore whether and when listening to a fast (vs. normal) heartbeat sound shaped ethical behavior. Study 1 found that perceived fast heartbeat increased volunteering for a just cause. Study 2 extended this effect to moral transgressions and showed that perceived fast heartbeat reduced lying for self-gain. Studies 3 and 4 explored the boundary conditions of this effect and found that perceived heartbeat had less influence on deception when people are mindful or approach the decision deliberatively. These findings suggest that the perceived physiological experience of fast heartbeats may signal greater distress in moral situations and hence motivate people to take the moral high road.