More than one in three young girls believe women are judged on beauty not brains, a new survey has revealed.
According to the Girlguiding's Girls' Attitudes Survey 2016, 36% of seven to 10-year-old girls also said they were made to feel their looks were their most important attribute.
of girls said they do not feel pretty enough.
said they felt the need to be "perfect".
Some 15% of girls said they also felt embarrassed or ashamed about they way they looked, the study found.
Campaigners said the survey's findings highlight the need to combat the "objectification and harassment" which are "ruining girls' lives".
The report shows that there has been a five-year decline in levels of body confidence among seven to 21-year-olds.
In 2011, almost three-quarters of girls (73%) said they were happy with the way they looked, compared to just 61% this year.
Sam Smethers, chief executive of the Fawcett Society, said women and girls were "persistently" judged on their looks and suffered "significantly" higher rates of depression and mental illness.
"This is serious - as a society we need to face up to the fact that objectification and harassment is ruining girls' lives and we are letting it happen," she said.
The Girlguiding Association has launched a social media campaign to encourage people to praise young women using the hashtags #YouAreAmazing and #GirlsAttitudes.
If we are serious about ensuring that everyone has an equal opportunity to get on in life, then much more must be done to ensure a level playing field - starting from childhood and into young adulthood, not least by challenging gender stereotypes.