Only-child Britain: UK families are shrinking in size as number of homes with just one child increases by a FIFTH The average number of children in a family is now 1.7, compared to more than two a generation ago, while the ONS found larger families are more like to not have a parent in work Dr T.E. Apter, Professor of Psychology at Cambridge University, says: There is a concern that singletons will not learn to share, and will grown up "spoiled." There is however little evidence for this. Though children do learn a great deal from siblings, and generally benefit from the cooperation and competition they practice on a daily basis among siblings, singletons also live in a world populated by other people, with whom they identify and with whom they have to compete, and with whom they learn to share. They have many opportunities to learn from their friends about closeness and conflict; they have many opportunities to learn that they cannot have everything their own way; they have many opportunities to learn that they gain a great deal through sharing. Humans are naturally social beings, and generally want to contribute to their society. Incidentally, singletons tend to be very curious about what having a sibling would be like, and wonder what kind of a sibling they would make. Sophie Zadeh, Psychology post-graduate at Cambridge University adds: 'Research to date seems to indicate that it is the quality of family relationships, rather than the number of people in a family, that matters most for children's social, psychological and emotional well-being. Some of our latest research has been on single women who have used a sperm donor to have a child. Some of these homes are comprised of mother and (only) child and these children seem to be functioning well. Caroline Jones with her daughter Mia Parents who choose to have only one child face being called lazy and selfish, according to mother-of-one Caroline Jones. She said she has been challenged repeatedly by friends and families over when she and husband Colin are planning a younger brother or sister for daughter, Mia. The idea of a huge close-knit ¬family, living constantly in each other's pockets, never held any attraction for me. It sounded far too chaotic and claustrophobic," she wrote last year. My rule of thumb has always been that there should never be more children than bathrooms in a home. Before you have children, people hold back a little. After all, you may have undisclosed fertility problems and be secretly desperate for a baby. But once you've had one child, it's open season. People just ask outright as if they're talking about the local bus service: "So, when's number two going to arrive?" My view is that, unlike parents of large families, we will be able to devote all our time, money and love into turning Mia into a happy, ¬confident little girl. And a raft of recent research backs us up. Obviously one key factor is that we're all feeling the economic pinch, with ¬parents simply unable to afford the extra cost of another child (a staggering £1,800 before they're even born, according to one survey last month). Another huge factor in the rise of single-child families is the trend for women to have babies later in life. UK birth records show that a woman having her first child at 35 is much less likely than a 25 year old to have more children. As fertility declines post-35, many women just run out of time. At the end of the day, it's not about romance, money, the agony of childbirth or all the research that proves how damaging sibling rivalry can be. The honest truth is that Mia is all I want. She's perfect and I'm done. So no matter how many times I'm asked when I'll be having my next one, I won't be changing my mind.