Older people often talk about how they knew they had gone too far with their mothers. While a father might yell more a mother's tone would change into "that voice" and they knew they had gone over an invisible line.

Today, it doesn't work so well. At least in controlled experiments - your mileage at home may vary. A study involving over 1000 adolescents aged 14-15 is the first to examine 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 and the authors conclude supportive tones of voice are better and that teens are much more likely to engage with instructions that conveyed a sense of encouragement and support for self-expression and choice.

The work involved 486 males and 514 females, aged 14-15. In the experiment each of the subjects was randomly assigned to groups that would hear identical messages delivered by mothers of adolescents in either a controlling, autonomy-supportive, or neutral tone of voice.



In experiments, this is fine, in your actual home use some judgment about when to tell your mother she needs to speak to you with "encouragement" and "support for self-expression and choice."  

Expressions of control impose pressure and attempt to coerce or push listeners to action. In contrast, those that express 'autonomy support' convey a sense of encouragement and support for listeners' sense of choice and opportunity for self-expression. 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 that the tone of voice used by mothers can impact significantly on teenagers' emotional, relational, and behavioural intention responses.

Across most outcomes, adolescents who listened to mothers making motivational statements in a controlling tone of voice responded in undesirable ways. In contrast, autonomy-supportive tones elicited positive reactions from listeners as compared to listening to mothers who used a neutral tone of voice to deliver their motivational sentences.

This may be fine in Wales but if you are a kid in the southern U.S. it might be better to not try this experiment at home.