A new study has found firstborn children are more likely to be 'emotionally available' and sociable to their mums, the Daily Mail reported.
For the study, researchers examined close to 55 mothers playing with their first or second child at 20 months. They found the firstborns showed more enjoyment playing with mum and was more will to respond to her suggestions.
"Firstborn children may be more sociable and emotionally available to their mothers because they have the benefit of years of their parents'undivided attention," Dr Diane Putnick, who co-led the study from Eunice Kennedy Shriver national Institute of Child Health and Human Development, in Maryland (US), is quoted as saying by the Daily Mail.
Adding, "Perhaps this concentrated time with mothers early on leads firstborn children to develop better social skills in relationships with adults."
The study's findings were originally is published in the journal Social Development.