The poll, commissioned by National Family Week, reveals the influence of technology on youngsters - and the extent to which parents underestimate it.

Some 28% of the eight to 15-year-olds questioned cited websites such as Facebook, Twitter and MSN as the most important thing to them.

Social networking had a bigger effect on girls than boys. Asked to name what is most important to them, the top three choices for girls were popularity and having friends, followed by family, and then social networking sites.

For boys, the top three were family, followed by money and then popularity and having friends. Just 6% of boys chose social networking, compared with four in 10 girls.

The study, which surveyed 3,000 parents and 1,000 children across the UK, reveals parents overestimate the role they play in their child's life.

Two-thirds of parents (66%) said they thought they were the biggest influence in their child's life. But only 49% of children said the same.

The survey also examined how youngsters feel about spending time with their families.

More than a quarter (26%) of boys did not think they spent enough time with their family, compared with one in six (16%) girls. One in four boys wanted to spend more time with both their parents, compared with 15% of girls.

National Family Week, backed by organisations including the NSPCC and the National Literacy Trust, encourages families to spend more time together. The week runs from May 31 to June 6.