An excerpt from the BPS Blog:

Aspects of the environment that indicate danger – from flashing lights to a mere exclamation mark – lead us to make faster and more extreme judgements about fairness.

Kees van den Bos and colleagues say this happens because when we sense a threat, and what they call the ‘human alarm system’ is activated, we tend to form faster and more extreme reactions, with justice-related decisions being no exception.

In one experiment, university students stared either at an exclamation mark for one minute, or at a line with a dot above it – the latter serving as a control condition. Next the participants played a computer-based task with what they thought was another participant, but was really just a computer programme. Afterwards, some participants were asked how lottery tickets – a reward for taking part – should be shared between themselves and their playing ‘partner’, based on their performances. The remaining participants were told the lottery tickets would be distributed without seeking their opinion. Finally, the participants were asked to indicate how fair this system of ticket allocation was.

Amazingly, the mere act of staring at an exclamation mark significantly affected the participants’ reactions. The difference in fairness judgments between those who’d been given a say and those who hadn’t was greater among the participants who’d previously stared at an exclamation mark than among the control participants – in other words their judgments were more extreme (those who’d been given a say responded more positively, those who hadn’t, responded more negatively, relative to the control participants who had and hadn’t been given a say).

Another experiment asked dozens of shoppers on the streets of Amersfoot in the Netherlands to imagine a scenario in which their colleague had either received the same or a larger bonus than they had. Half the shoppers were asked near to a flashing road-work light – their subsequent judgements on the fairness of the bonus allocation were more extreme than those asked with the light switched off.

VANDENBOS, K., HAM, J., LIND, E., SIMONIS, M., VANESSEN, W., RIJPKEMA, M. (2008). Justice and the human alarm system: The impact of exclamation points and flashing lights on the justice judgment process. Journal of Experimental Social Psychology, 44(2), 201-219. DOI: 10.1016/j.jesp.2007.03.001