“He needs to toughen up.”

It’s a line we’ve all heard more than once – sometimes from grandparents, from friends, or even from ourselves. We watch our children grow and we worry. We imagine them alone at school or moving out on their own and wonder how they’ll hold up when we’re not there to protect them.

We want our kids to be wildly successful adults, and so we spend our time worrying about the right way to discipline them, the right way to encourage them – the right way to manage every minute of our lives around them.

In the end, though, the thing that matters the most is love.

Whether you use the newest parenting techniques or trust the old wisdom, your children will grow up well so long as you love them. Parents who touch, talk and play with their kids, who are patient with them, and reassure them when they’re worried make great kids every time.

That’s not just sentiment – it’s fact. Parenting research has proven time and time again loving your children is the one thing that makes all the difference – in so many important ways.

Love makes a child’s brain grow.

From the very beginning, your love for your children affects how they develop. Your child’s growth has to do with more than just the food they eat and the exercise they get – love affects it, too.

Researchers looked at how well mothers supported their children when they tried to do a difficult task, and then checked back about 5 years later to do a brain scan. The more supportive the mothers were, the more the child’s brain – specifically the hippocampus – had grown.

This part of the brain controls how kids learn, how much they can remember, and how they handle stress. Children that are supported by their parents when they struggle get more than just a little help – they get bigger brains.

Supporting your children improves their self-esteem.

Sometimes, it’s tempting to raise a self-reliant child. We want our kids to be strong on their own so that they can learn how to believe in themselves. If they handle their problems on their own, we might imagine, they’ll get stronger.

It turns out, though, a child’s self-esteem really comes down to how much their parents support them. A study on middle schoolers found that the more kids felt their parents supported them, the stronger their self-esteem was. In particular, this had a big impact on girls, who need that external support just a little bit more.

As long as we believe in our kids, they’ll copy us – and they’ll believe in themselves.

Parental warmth makes healthier kids.

Loving your kids doesn’t just make them smarter and more confident – it even makes them healthier. One study sought to find out how childhood abuse led to heart problems later in life. What they found, though, was that it wasn’t just abuse that affected kids’ health – it was every little bit of love.

The more children felt like their parents gave them warmth and affection, the healthier the kids were when they grew up. Even when a child has been abused, their risk of cardiovascular diseases, cholesterol issues, heart disease, stroke and diabetes will go down – as long as they’re given a loving home.

Believing in your children improves their grades.

We try a lot of different things to help our kids succeed. We might fill them up with extracurriculars to strengthen their minds, or lighten their load to let them focus on school. We might push them to work hard on their homework or encourage them to let out some of that stress.

The thing that really makes the difference, though, is just believing that they can do it.

A study looked at how much parents believe their children can succeed, and found it made a huge difference. When they followed up a few years later, the kids whose parents consistently believed in their abilities earned significantly higher grades – an average, 0.21 higher GPA – than their less supported peers.

So try whatever parenting styles you feel you need to try. But remember, as long as you show your kids that you believe in them, as long as you offer them love, warmth, affection, and support, your kids are going to be just fine.