A mother's state of mind rather than her teen daughter's stroppy attitude is the key to surviving adolescence, according to new research.
Adolescence was a tough time for both teenage daughters going through puberty and parents having to cope with their emotional roller coaster of changing hormones.
Now scientists have found the exact formula so that mums and daughters can survive those turbulent years (soundtracked here with Spice Girls Mama).
If teenage girls can manage their emotions and both are flexible in coping with the changes their relationship may stand the test of time, Canadian researchers found.
Those mums and daughters who struggled to adapt had the worst relationship quality afterwards, researchers at Queen's University, Ontario said.
But it was the mother's mental health rather than the daughter's which was key to how the relationship fared.
If mums had depression and anxiety, her relationship with her daughter was more likely to be doomed.
Co-author Dr Jessica Lougheed in the department of psychology said: "This study reflects a growing need to examine how typically developing adolescents - those without a diagnosis of any major mental health issue - learn to manage their emotions.
"Being able to effectively manage emotions in different kinds of emotional contexts - called 'emotion regulation' - is a crucial part of healthy development."
The study examined how mother-daughter pairs were able to manage transitions between emotional states.
They questioned 96 typically developing adolescent girls and their mothers individually about the quality of their relationship and whether symptoms of anxiety and depression were internalised.
The mums and daughters then answered a questionnaire on times when they felt happy, worried, proud, frustrated, and grateful toward each other and took part in a series of three-minute conversations about those emotional experiences.
Researchers then analysed the emotions they showed throughout the videotaped sessions.
Unsurprising, mums with less anxiety and depression symptoms, alongside 'moderate levels of flexibility' throughout the changes, had a better quality relationship.
But, the most flexible mums and daughters showed no links with relationship quality or mental health - suggesting that a moderate degree of flexibility is optimal for a strong and healthy relationship.
Associate Professor Tom Hollenstein said: "We have speculated, but never tested the hypothesis, that flexibility is sort of an inverted-U function in terms that a certain amount is just right, but too much and you become disorganised and leaning towards a lack of coherence".
The findings showed that it was the mother's depression and anxiety, as opposed to the daughters, that was consistently related to the degree of flexibility.
Dr Lougheed added this showed adolescence was not just a time of development for children, but a developmental transition for parents as well.
She said: "The adolescent developmental period is an important transition for parents and adolescents alike.
"Generally speaking, parents and teens who are able to 'go with the flow' of new emotional experiences in their relationship will likely be show better well-being in other ways as well."
The study was published in the journal Emotion.