At the launch of her book The Psychology of Babies, Lynne Murray offers practical advice on how-and how not-to get a baby to sleep, reports The Daily Mail.

Lynne Murray, a professor of developmental psychology, said that babies take note of what is going on as they drop off – and come to want the same thing each time.

So a baby that becomes used being held will need to be rocked in order to fall asleep in the future.

Similarly, a mother who allows her baby to nod off while breastfeeding can expect to have sleepless nights ahead.