Children living with a step-parent or a lone parent are as happy as those living with two biological parents, a study indicates. In a major UK study on wellbeing, researchers analyzed data from 12,877 children aged seven in 2008, and found no significant difference in happiness. Whether the children lived with two biological parents, a step-parent and biological parent, or in a single parent family, made no difference to how they rated their happiness: 64% said they were happy 'sometimes or never', and 36% said they were 'happy all the time'.