How social bots tip the scales in public debate on social media

Amtrak's chatbot telling the user it's not human. — dpa

Release the bots! Software-generated tweets and fake Instagrammers are well capable of shaping public opinion, a new study on the impact of social bots has shown.

Even a small number of social bots in a social network can be enough to steer the mood in one direction or another, a study has found.

Social bots are pieces of software that mimic human beings on social media networks, generally with the aim of advocating certain opinions or supporting campaigns.

Researchers at the University of Duisburg-Essen in Germany created a network of 1,000 virtual participants. The assumption was that half of opinions on a given topic would be positive and half negative.

Without the social bots, one side got the upper hand half the time. But even a small number of bots were sufficient in a controversial discussion to tip the balance. The probability increased from 50% to 66% that the side supported by the bots would come out on top.

"The results indicate that, in a highly polarised setting, depending on their network position and the overall network density, bot participation by as little as 2%–4% of a communication network can be sufficient to tip over the opinion climate in two out of three cases," the study says.

The researchers concluded that bots are able to trigger the phenomenon known as the spiral of silence – that's where people don't express their opinions if they think they're in the minority.

The success of the bots in exerting influence depended on three factors: the number of connections between users, whether the bots were central to the network or on the fringes, and also the quality of their programming.

The more human-like a bot acts, the more successful it is. Even so they're not so perfect that they can't be identified as not being human. – dpa