Crying in the first 12 months of life: A systematic review and meta-analysis of cross-country parent-reported data and modeling of the "cry curve".

Crying is an ubiquitous communicative signal in infancy. This meta-analysis synthesizes data on parent-reported infant cry durations from 17 countries and 57 studies until infant age 12 months (N = 7580, 54% female from k = 44; majority White samples, where reported, k = 18), from studies before the end Sept. 2020. Most studies were conducted in the United States, the United Kingdom, and Canada (k = 32), and at the traditional cry "peak" (age 5-6 weeks), where the pooled estimate for cry and fuss duration was 126 mins (SD = 61), with high heterogeneity. Formal modeling of the meta-analytic data suggests that the duration of crying remains substantial in the first year of life, after an initial decline.