Although when in full cry the Twitter pack might appear otherwise, people are not (often) drooling dogs, salivating at the ring of a bell. But no matter how lofty our ideals, or how high our altruism, we all respond to incentives.

The main incentive in social media – Twitter, Facebook, blogs and similar – is approval from your peers, and those you respect. In the absence of any tool to express the contrary, such approval takes the form of ‘likes’, ‘favourites’, and repetition in the form of re-tweets and shares. Twitter in particular has extensive supporting tools which allow you to track these ratings of approval, and a range of companies and consultancies who will happily analyse your performance and help you improve.

The snag is that having only tools of approval sets up an unstable control system: a positive feedback loop. It is like a car with only an accelerator and no brake, or a lift with only an up button, no down.

One positive feedback loop with which I am only too (perhaps bitterly) familiar is that of temperature and finger (or toe) bloodflow. When skin temperatures fall, that causes a reduction in local bloodflow. A reduction in local bloodflow causes the skin to cool further. Unless you are so warm that your body can override this positive feedback, your fingers or toes just get colder and colder.

In a peer group which reinforces particular behaviours – loutishness, insults, or bullying, perhaps – the presence of that positive feedback loop results in a vicious circle, driving worse behaviour. This fuels extremism and excess, just as the piercing howl of guitar-speaker feedback (another example of a positive feedback loop).

Of course there are ways that we can respond negatively to social exchange, but they often lead to polarisation and not placation. In face-to-face communication, even the most intense arguments often end with ‘kiss and make up’ rather than shouting and tears; online entrenched hostility seems to be the inevitable outcome.

The social media need to think seriously about how they can introduce potent but progressive negative controls in their interactions. Or they will always bring out the worst in people.