How we change what others think, feel, believe and do
We feel sad when we realize that we are unlikely to achieve our goals, and especially when we have put a lot of effort into achieving them. Initially, this may trigger anger, but this never lasts for long and we are left in the miserable state of sadness.
Sadness may not last for long or may persist, depending on the goal that has been frustrated. Of all the emotions, sadness tends to that which lingers longest.
Depression is an extreme forms of sadness, where people stay sad for a long time and cannot see any way out of their state.
Sadness is generally considered to be the opposite to happiness, although the complexities of these emotions mean this is more of a general statement than an exact one.
Sadness can be triggered by things that remind us of sad times, from down-beat music to tragic plays. Just being around depressed people is, well, a depressing experience. Loss leads to sadness and even to grief (an extreme form of sadness), where things that once felt a part of our identity are taken away from us. This can happen when we sell or throw out our old things, when a friend leaves, when people die, and so on.
Internally, sadness is caused by a lack of seratonin being created in the brain. Happy people produce lots of seratonin, whilst sad people produce very little.
Sad people tend to be more pessimistic and cautious. This appears in such as shopping habits, where sad people will look dolefully, but buy very little and very boring things.
Sadness is not a permanent state, and time is a great healer.
When people are sad, they often slow down rather than act in an elevated, excited way. They may seek solace with others, wanting to tell their tales of woe, or they may spend more time by themselves.
Listening to music
When we are sad, we may listen to music, which may be sad music but not necessarily so. Van den Tol and Edwards (2013) found that this could be because of:
Music may intensify the listener's sadness, yet in doing so it helps them work through their sadness and so more quickly return to a normal emotional state. As a distraction, it takes them away from the unbearable pain of sadness, at least for a while and perhaps re-energizing them so they can face the sad news more comfortably.
If someone is sad and you want them to be happy, reframe their goals to something they can achieve in the short term.
Do not try to sell things to people when they are sad, unless that state really is important.
Verduyn, P. and Lavrijsen, S. (2015). Which emotions last longest and why: The role of event importance and rumination, Motivation and Emotion, 39, 119-127.