Fitting with the surrounding is needed when it comes to appearing mature. Nervousness, hesitation, uncertainty, etc are all signs of lacking maturity. Mature people know what they are doing and they have experienced enough to stay hopeful in any situation. Hence, confidence is essential to appear...

We often make fast gestures and talk so fast that it appears to the other person as we are less mature.

Moreover, fast gestures and speech are signs of nervousness, discomfort, unstable emotions, lacking self-control, etc. So, it is best to slow down and communicate at a normal pace.

Sometimes, we change the subject matter of the conversation unconsciously. What happens is that the person feels that we aren't paying much attention and that our mind/ thoughts are not stable. Therefore, it's best to stay within the topic.

Same as the other ideas, displaying a lack of self-control is another factor. Complaining about something because it didn't go in our way, feeling empty at hard times, aggressive behaviors are all features of low self-control and also low emotional intelligence. 

In this case, controlling e...

Interestingly, our getup also matters. In fact, in experiments, younger people tend to choose light colors and older choose darker. Flashy clothes also indicate childness. Even our hairstyle makes us look irresponsible. It's human psychology to judge someone based on their getup. 

So in thi...