How many immigrants per year should Switzerland be prepared to welcome? Do the figures put forward by political parties and conveyed by the media play a role in influencing public opinion? Psychologists from the University of Geneva (UNIGE), Switzerland, set about testing a well-known form of reasoning bias called anchoring bias—it consists of providing a deliberately low or high figure for information purposes before respondents give their opinion on a subject. The researchers found that the figure supplied played a vital role in shaping respondents’ opinions, regardless of their political orientation or the political party responsible for the figure. The research, which is published in the Journal of Applied Social Psychology, points out the dangers of numbers-based political votes, since public opinion is easily swayed by the first number conveyed in the media.