Many mothers and fathers believe social media is hampering their child's moral development, according to a survey.
It suggests the majority of parents do not think these sites are a positive influence on a young person's character, while some are concerned about the negative impact they can have.
The poll is part of an ongoing study by the Jubilee Centre for Character and Virtues at Birmingham University.
Overall, some 55% of around 1,700 people with children aged 11 to 17 who were questioned strongly agreed that social media hinders or undermines a youngster's moral development.
Around one in six (15%) generally agreed that these popular sites can have a positive impact.
In addition, 40% of those polled said they were concerned or extremely concerns about the potentially damaging impact of social media on children.
Researcher Dr Blaire Morgan said: "There are some surprising findings in the poll, not the least the low level of agreement that social media can enhance or support a young person's character or moral development.
"Whilst parents acknowledged that positive character strengths, including moral virtues such as love, courage and kindness, are promoted through social networking sites, they were reluctant to agree that these sites could have a positive impact on their child's character."
The survey, which questioned parents about their own use of social media, asked mums and dads which negative traits or vices they see on these sites at least once a month.
Three in five (60%) said they had seen anger and hostility, followed by arrogance (51%) ignorance (43%) bad judgment (41%); and hatred (36%).
But almost three-quarters said they see content containing a positive message at least once a day.
Dr Morgan said: "The Jubilee Centre's parents and media project seeks to explore the relationship between social media and virtues in more depth, and hopefully offer a more constructive outlook on how social media might impact on a person's character and moral values.
"Social media is not going away, so by learning more about this relationship we should be able to maximise the benefits of social media use and avoid the pitfalls."