During congress era, there were government spies who enters or gain access to an organization or political parties gradually especially in order to gain information from underground political replies. these spies were thoroughly trained in order to catch a person who clapped first. they take photos and information of that particular person who clapped first and shouted bravo in high pitched voice and  one who smiled the longest after inflamatory political speech. The agents give them a nickname as the most dangerous and threatening person. The agents feel as the one who reacts first or respond first are the confident one, they had the power to motivate and persuade people and they have the quality of a leader and they can give direction to large no of people listening to them. 

similary during presentations or meeting the person who respond first are the confident one who don't care much about other people reaction sitting around. this quality is known as leadership quality. 

Cool and confident cat clap first. 

Suppose you are sitting in an auditorium and listening to your managing director of your company introducing about new projets you think its bored and so you are sitting in a lazy way because you think the person standing on podium will not recognise you and is not noticing your moves you are wrong the person on the podium can see and notice every subtle moves. 

similary one of the president making presentations watch his or her concrete corporate jungle and continuously analyzing the one who is paying attention to him and the one who are sympathetic and president who is among the mob is a big hitter like him? 

because if you notice heavy hitters always support the speaker who is standing at the podium because you know why? big hitters always support the person and agree with the speaker even though he does not agree because heavy hitters knows that its don't matter whether the speaker is small or very big personality, when they are giving any speech they care all about crowd acceptance. so you should be the first to applaud or publicly commend the man you agree with or you want favours from. it doesn't matter how big or prominent the famous big person behind the podium giving speech but that big person is frightened inside because he is expecting crowd acceptance. so when big shots deliver his last line deliberately created to bring the crowd to its feet do you think he is unaware of who start first clapping no way