Parents may turn their children off learning if they simply resort to promising rewards and fail to explain why something is worthwhile, it has been suggested.
Offering youngsters money, treats and other benefits for scoring top grades may encourage them to work to pass a test but will not help them to stick with a subject, according to Julia Harrington, headmistress of Queen Anne's School in Caversham, Berkshire.
She said there is evidence that explaining to children the long-term benefits of learning something, such as an instrument or a language, and tapping into a youngster's natural curiosity and motivation, is more likely to help them master it.
Mrs Harrington told the Press Association that research has shown there is a difference between intrinsic motivation, such as children feeling in control of their own learning and wanting to master something themselves, and extrinsic motivation, such as promises of rewards.
She suggested that mothers and fathers should try to trigger their child's interest in a topic, explain why they might find it interesting and focus on long-term learning rather than short-term goals.
"Give them a reason that lies within their motivation to make them want to do it," she said.
"Don't say 'I'll give you a fiver if you get an A in the next test'. Because they will get an A in the next test but they won't stick with the learning."
Mrs Harrington added: "Children are naturally curious and if you trigger that curiosity and if they want to know, so they understand the thing that they really love, then that will help them."
The headmistress suggested that parents should trust their own instincts, teachers and their child's school and "find the things that will form good intrinsic motivation, which includes a child knowing why they're doing it, having choice, having some autonomy and choosing mastery over goal".
"So becoming fluent in Spanish rather than having an A in a test," she suggested.
She added that parents should set standards "high enough to challenge and motivate, but not so high that it seems unattainable".
Dr Kou Murayama, of the University of Reading, has conducted studies examining links between motivation and achievement, including one which looked at whether parental aspiration was a predictor of achievement in maths.
The study, which involved students and their parents in Germany and the United States, found a positive relationship, he told the Press Association.
But it also showed that differences between parents' aspirations and their realistic expectations can have an impact.
It concluded that unrealistically high parental aspiration impaired children's performance in maths.
"We need to raise children believing that they can do well, but if you have unrealistically high aspirations then you're going to have a backlash, it is going to backfire. It's good to have high aspirations, but not too high."
He said it can be quite difficult for parents to know how far to push their children, but that they should think about the way in which they do so.
Mothers and fathers should give reasons why they are encouraging a child to learn something, he said, be sympathetic towards them and give them a choice in what they do.