Pay attention to the situations in which your child laughs too much; this will help you to understand the problem better.
If your child is laughing without any specific reason or if (s)he is talking, crying or staying silent way too much without any understandable reason, this might indicate that your child is unable to understand what is going on in a particular situation.
When children have insecurity of being judged as someone who cannot gauge what is going around in his/her space, they react in a way in which people around them are not able to catch the fact that the child is not understanding anything happening around him/her.
From the child’s perspective, (s)he feels, "Come on! I don’t get it. Why do you want me to understand everything”. They choose not to be vocal about how they feel. So they keep reacting in odd ways. Sometimes children are scared and think "If I go say that I don’t understand this and ask again, my parents will get angry and scold me.” You need to analyse the scenarios in which your child laughs too much. Ask you this question - Is this situation particularly funny and laughable or is my child just acting oddly because of (s)he lacks understanding of the situation?
If you feel that your child lacks understanding, talk to them in private and ensure them that you are there to understand them and not mock them or be angry at them. Reassure them that if they don't feel right about anything, they can come to you and talk to you; there will be no judgements. If things are out of control and you cannot help manage your child's behaviour, you should consult a child psychologist who can help you solve this problem by taking steps in the right direction.
Being a positive role model for your child can help instil the right attitude and habits from an early age for your child to nurture a healthy lifestyle.