In a discussion, one’s opinion about a certain proposal is influenced by his opinion of the person suggested it. If we consider the person making the offer as an antagonist, we tend to value the proposal as being less interesting than if it was made by someone else. This cognitive bias is known as reactive devaluation and can affect your decisions as well as block your influence in conversations. It is frequently observed in all kinds of negotiations and can lead to sub-optimal outcomes for both parties since good ideas might be rejected just because of the people giving the ideas. Researchers have shown that the bias is a result of loss aversion, perceptions, preferences and attitude polarisation. To avoid this bias in negotiations, working with a third (neutral) party can be an effective solution.
A sidewalk survey was made in 1986 where pedestrians were asked if they would support a nuclear arms reduction plan. 90% of the participants answered they would if they had been told that President Ronald Reagan made the proposal but this number dropped to 44% when they had been told that Mikhail Gorbachev made the proposal.