Last month the Senate blocked the passage of the gun control amendment, dealing a crippling blow to President Barack Obama's campaign to curb gun violence after the Newtown school massacre. According to some media President Obama responded to the vote by saying he was disappointed. Other media described Obama’s response as angry. Are these two negative emotions so similar that people can mistake one for the other? And what is more effective in such a situation, communicating anger, or communicating disappointment?

Emotions affect no only one’s own behavior, but also that of others. Expressions of happiness, for instance, communicate that things are going great and it can motivate others to pursue their current course of action.

So what about anger and disappointment? Anger and disappointment are both negative emotions and reactions to undesirable outcomes, but they affect others’ behavior in a very distinct way.

Anger is an emotion that communicates power, whereas disappointment communicates weakness. In negotiations, anger often elicits concessions because it signals toughness. Angry individuals are perceived as uncompromising negotiators who do not want to give in. To avoid having the negotiation end in an impasse, receivers of anger end up giving in. In situations where people have low power, however, communicating anger backfires. In this situation, receivers do not have to be concerned with the negative consequences of the angry opponent and they do not give in.

Also, when you communicate anger, you should direct it at the situation, and not at the person. In the latter case, targets become angry themselves and do not give in to the angry bargainer.

So the communication of anger can be advantageous, but in certain situations it can also backfire. Communicating disappointment may then be a better alternative.

Often children feel worse after their parents say they are disappointed in them, than after they express anger. You might remember sitting across the kitchen table from your parents, hearing them say that they are not angry with you, but “just” disappointed. Indeed, the expression “I am not angry with you, I’m just disappointed” is often used to make people feel bad about what they have done, in hopes of changing their behavior.

So, should Obama have communicated disappointment when he presented his arguments to expand background checks on gun buyers? Our own research on the effects of communicating disappointment has shown that disappointment communicates weakness. Yet, in contrast to the common belief that weakness is a liability, expressing disappointment can be highly effective. A crucial determinant of whether communicating disappointment helps or hurts is whether or not it evokes guilt in others. Research has established that disappointment can indeed evoke guilt in others. Guilt improves relationship quality, reduces competition, and motivates people to make amends. Thus, this suggests that it can be very advantageous to communicate disappointment, as long as it evokes guilt in others.

Our research has shown that disappointment is more likely to evoke guilt when it is directed at a person instead of the situation, and when the receiver of the emotion is a member of the in-group member (one’s own group, in Obama’s case the Democrats), instead of an out-group (another group, in Obama’s case the Republicans). When expressing disappointment does not evoke guilt in others, targets take advantage of the weakness and are less inclined to give in.

Anger and disappointment are thus indeed two completely different emotions, with different effects on others. But what emotion should Obama have communicated to the Republicans to make them give in, and vote in favor of the plan to expand background checks? On the basis of the findings that disappointment backfires when it is communicated to out-group members, one may conclude that it is not that effective to communicate disappointment. Anger, on the other hand, is effective when communicated by a high-power individual, as long as it is directed at the situation and not at the person. Although it is hard to imagine that Republicans will change their minds because of the emotional expressions of Obama alone, communicating the negative emotion of anger may be more helpful in this situation.