Like AAWM says, every kid is different. Some kids are more advanced physically - with crawling and walking. Some kids are more advanced verbally - babbling and then forming words. I don't think your son is behind, from what you're telling me. Most kids don't really pick up on the crawling until they're 8/9/10 months old, and a lot of kids don't walk until they're 1 year or more. (I didn't walk until I was 18 months.) As for talking - my son is 20 months, and he's only now beginning to form words. What you can do is work on these things with him. You say he's not pulling up - how much tummy-time does he get every day? He should be getting at least 10-15 minutes or more. You can encourage him to reach for things by putting his toys at arm's length. You can encourage babbling by talking to him constantly, and repeating the noises he does make. Teach him how to wave by waving at him, and helping him wave his hand back at you. Bottom line: talk to your pediatrician. If he/she isn't worried, you shouldn't be either. Your son will do these thing at his own pace.