insight on children s sleep patterns. a recent study suggests genetics play a key role how long kids sleep at night. while environment, you know the sleeping environment, is a major factor in the kinds of afternoon naps they take. dr. nina radcliffe is a practicing physician and a new mom. so let s start with your baby. is your baby sleeping at night, dr. radcliffe. absolutely. it took a lot of effort. i read every single book i could get my hands on and tried every gimmick and every wife s tale to get my baby to go to sleep. jon: they did it in an interesting way using twins, how much your child sleeps at night in large part is determined by genetics. that is interesting because identical twins have identical genes as opposed to fraternal twins who have different genes. when they tried to differentiate between genetic and environmental this is what they do. found that children get a good s night sleep most likely it is because of