Question: My daughter seemed to be developing at a normal rate until about the age of 10. She then started to act younger than she is. 

Now she only wants to play with younger kids and she doesn't act her age. I don't know why this is happening. Is this normal?

Response: Hello.It sounds like you are really concerned about your daughter because you have noticed a significant change in her behavior .   It's really a great first step that you are reaching out to get some ideas about what might be going on .  You are clearly an observant and hands on  mom who wants to be sure that her daughter is ok.This is a tough question to answer without more information .  With that said , I have found that "under stress people regress."  In other words , many people , children and adults alike , often regress and behave differently - as if they were younger than their actual age - when under stress .   Therefore , my first question would be : has anything been happening recently that is causing your daughter stress ?  This could be anything from conflict at home , recent changes such as moving , divorce , a loss of some kind , switching schools , or losing a friend or friends .   Additionally , sometimes if children are feeling bullied or left out by same age peers , they may gravitate toward younger playmates as a way to boost their social confidence .    I would suggest that you think about what stressors / changes may have occurred recently.  You may also want to check in with her teacher (s) to see if they have noticed any changes in your daughter's behavior at school .I also think that you can have a conversation with your daughter in order to see if you can get a sense about whether or not something has been bothering her.  Something as simple as " I have noticed that you aren't spending time with the friends you used to hang out with ; it seems like you have been playing with a lot of younger kids lately .  Am I right about that ? " and then if she says yes you might ask a few questions such as : "did something happen with your friends that  is making you not want to be with them?" "Has something been bothering you lately ? Are you feeling upset or worried ? " If she denies that there is anything wrong you might even say " I know that sometimes when I feel stressed or worried , I tend to act a little differently - sometimes I withdraw from my regular group of friends , or I get cranky and feel less like myself .  I wonder if something like that is happening with you ?" If you are really concerned and not getting any answers from her and / or her teachers , perhaps you can consult with a therapist to discuss your concerns further and decide if it might  help for your daughter to talk to a therapist a few times , or at the very least you can get more specific tips from a therapist about how to approach this issue with your daughter more effectively . The more detail you can provide about what you have noticed with your daughter , including any changes or new stressors ,  any possible patterns to this behavior , if school has become more difficult socially and or academically , the more a therapist can guide you about how best to handle your concerns and talk with your daughter in a way that is helpful to her. Good luck!   I believe that this may just be a phase and it seems to me to be well within the normal range of children's behavior.  I do, though, think that you will feel more assured about this  if you can get to the bottom of what's going on .