Young children experience transient periods of sensibility, and are intrinsically motivated or urged to activity by specific sensitivities. A child in a sensitive period is believed to exhibit spontaneous concentration when engaged in an activity that matches a particular sensitivity. For example, children in a sensitive period for order will be drawn to activities that involve ordering. They will be observed choosing such activities and becoming deeply concentrated, sometimes repeating the activity over and over, without external reward or encouragement. Young children are naturally drawn towards those specific aspects of the environment which meet their developmental needs.