A psychologist will tell you that the theory of reciprocity states that people respond to a positive action with another positive action. We reward kind actions and are much nicer and more co-operative with those who perform them.

Over Christmas, my 20-month-old daughter was given three festive treats by local businesses (not all independent): a white chocolate snowman, a gingerbread reindeer and a lolly.

While they were all lovely gestures, they created a sense of loyalty and willingness to go back and repay the favour. Plus my daughter says ‘lolly, lolly, lolly’ every time we walk past the shop at the end of our road.

The psychologist will also tell you reciprocity means that our response to hostile actions is to be much more nasty, even brutal.

For example, if you have always received something (say a certain payment for carrying out a service) and one day it’s taken away from you (or your margin is cut) your trust in the relationship will break down.

It is how society operates, how we are brought up and is ingrained in us all.

Yet it seems to be lost on newspaper circulation bosses who, looking at increasingly grim profit and loss accounts, see cutting retail margins as a quick way to make up shortfalls.

Those bosses will say that without claiming a greater share of the cover price the title might cease to exist at all.

But there is only so much hostility that can be shown to their route to market before angry feelings (see not just this issue’s letters page, but any week this year) turn into sharp retaliation.