Social-emotional 
A baby usually:

Is well aware of strangers and familiar people and withdraws from strangers

May not even go to familiar people for a while – demanding the person who looks after her most

Gives cuddles by 10 months

Enjoys peek-a-boo games

There may be a problem if a baby:

Does not show pleasure when she sees familiar people

Does not show anxiety when separated from the person who looks after her most

Motor skills 
A baby usually:

Can move around by crawling or bottom-shuffling by 10 months

Can reach out while sitting without falling over

Can pull up to standing by 10-11 months

Walks with hands held by 10-12 months

There may be a problem if a baby:

Is not sitting by 9-10 months

Is not starting to move around by any means

Understanding 
A baby usually:

Is interested in small objects and toys and reaches out for them

Starts to look at, feel and handle objects before taking them to his mouth

Looks in the correct direction for things that have fallen down

There may be a problem if a baby:

Is not interested in toys or objects that are attractive to babies of this age

Speech and language 
A baby usually:

Is putting strings of babble sounds together

Shakes head for ‘no’ by about 10 months

Recognises several words including own name (e.g. looks for daddy if ‘daddy’ is said)

Imitates simple sounds made by other people

There may be a problem if:

Babbling has not become more complex and baby does not babble in ‘conversation’ with others