Babies totally cry to communicate! Thankfully both dh and I are on the same page with this. We don't let DS cry and we know now that if he is crying it's because he needs us, ie he's teething, has gas pains and needs a belly rub, he needs his nappy changed, has stacked it and needs to be sat upright again etc. He has never cried for no reason! It's distressing to me when he's crying let alone leaving him to cry. Even if he just needs a cuddle, so what, we cuddle him! He's a baby after all and why wouldn't he want us to be holding him