1 month old doesn’t focus on faces....is that normal?

Is it normal for a 1 month old to not really be interested in his parents (or anyone’s really) faces? We also have a 2 year old and I remember (and have pictures and videos) her at this age looking right at us and even giving us some smiles and reacting to our facial expressions. Our second child is just over a month old now and he doesn’t seem to be interested in any faces and doesn’t seem to react to anyone’s facial expressions when he does glance over. Is this normal?