If you were wondering why your teenage child never listens to you, scientists may have the answer.

Teenagers are less likely to cooperate and put effort into their mother’s requests when they are said in a controlling tone of voice, Cardiff University researchers have found.

Speaking to a son or daughter in a pressurising tone is also accompanied by a range of negative emotions and less feelings of closeness, the new study has discovered.

The experimental study - involving more than 1,000 adolescents -  is the first of its kind. It examined how subjects respond to the tone of voice when receiving instructions from their mothers, even when the specific words that are used are exactly the same.

Lead author of the study Dr Netta Weinstein, from Cardiff University, said: “If parents want conversations with their teens to have the most benefit, it’s important to remember to use supportive tones of voice. It’s easy for parents to forget, especially if they are feeling stressed, tired, or pressured themselves.”

The study showed that teens were much more likely to respond to instructions that have a sense of encouragement and support for self-expression and choice.

The results, while of obvious interest to exhausted parents, could also be of useful to schoolteachers when speaking to students in their classrooms.

“Adolescents likely feel more cared about and happier, and as a result they try harder at school, when parents and teachers speak in supportive rather than pressuring tones of voice,” Dr Weinstein added.

What was the experiment?

The study looked at 14 and 15 year olds

The new study, published today in the journal Developmental Psychology, involved 486 males and 514 females, aged 14-15.

In the experiment, each teen was randomly assigned to groups that would hear identical messages delivered by mothers in either a controlling, autonomy-supportive, or neutral tone of voice.

Each of the mothers delivered 30 sentences that centred around school work, and included instructions such as: “It’s time now to go to school”, “you will read this book tonight”, and “you will do well on this assignment”.

After the delivery of the messages, each student undertook a survey and answered questions about how they would feel if their own mother had spoken to them in that particular way.

The findings showed the tone of voice used by mothers can impact significantly on teenagers’ emotional, relational, and behavioural intention responses.

Most of the time, adolescents who listened to mothers making motivational statements in a controlling tone of voice responded in undesirable ways - picture Harry Enfield's Kevin.

In contrast, autonomy-supportive tones created positive reactions from listeners as compared to listening to mothers who used a neutral tone of voice to deliver their motivational sentences.

Co-author of the study Professor Silke Paulmann, of the University of Essex, added: “These results nicely illustrate how powerful our voice is and that choosing the right tone to communicate is crucial in all of our conversations.”

The researchers now intend to investigate how tone of voice can impact physiological responses, such as heart rates or skin conductance responses, and how long lasting these effects may be.

The study was funded by the Leverhulme Trust and involved researchers from Ghent University and the University of Essex.