Poorer children are twice as likely as other youngsters to suffer from developmental difficulties when they start primary school, new research has shown.
At the age of five, those from poorer homes are significantly behind children from more affluent backgrounds, according to a report for the charity Save the Children.
The Thrive at Five report is based on a study of 3,000 children from different backgrounds across Scotland. It finds that children living in poverty are 40% more likely to be behind in cognitive development, reducing their ability to gain knowledge and learn.
Poorer children are twice as likely as others to have problems with physical development, twice as likely to have emotional difficulties when starting school and twice as likely to struggle with communication, including expressing themselves or making themselves understood. They are also 50% more likely to have problems with social knowledge, affecting, for example, their ability to mix with other children.
Douglas Hamilton, head of Save the Children in Scotland, said: "The long-term ramifications of these developmental difficulties for children in poverty are very serious. To discover that this developmental divide begins before a child even starts school is incredibly worrying.
"Ultimately, the consequences of this glaring gap are found in reduced future opportunities and life chances of children who live in poverty."
Save the Children is now urging the Scottish Government to do more to help these youngsters in their early years. It wants ministers to extend the right to free pre-school education to all two-year-olds living in poverty and wants poorer families to be given more access to parenting and family support programmes.
"Thrive at Five tells us that we must prioritise support for the children growing up in poverty before they even start school. There is some great work going on in Scotland to support young children and there is political agreement about the importance of the early years.
"The forthcoming Children and Young People's Bill provides an opportunity for the Scottish Government to commit to investing in early years education. Unless these actions benefit young children we will never stop this vicious cycle that keeps people poor generation after generation."
A Scottish Government spokesman said: "It is completely unacceptable that any child in Scotland lives in poverty. This Government is doing all we can within the devolved powers to tackle this problem head on, with the aim of eradicating child poverty by 2020."