Single mothers who use informal childcare arrangements after the first year of birth may be hampering their child's development, according to new research from the USA. But family campaigners have urged caution and say such findings must not be used to put more pressure on hard-pressed lone parents. The study looked at a sample of more than 1,500 single mothers from the USA's National Longitudinal Survey of Youth to evaluate the impact of maternal time and income on child development. It assessed results from vocabulary and...