Having a sibling is wonderful in many ways. It’s someone to share your childhood with and the only other person in the world who will understand when the house rules seem unfair. However, sibling relationships can also be complicated, especially in the first few years of life.

Even if you take all of the necessary steps to prepare a toddler for a new baby, sibling rivalries can creep up on you. It’s common for a toddler to feel connected and protective of a newborn sibling, but the minute his baby sister starts to crawl and wiggle her way into her big brother’s space, chaos can easily ensue. Thankfully, there are reasons for sibling rivalry that make sense, and things you can do to manage it.

What Causes Sibling Rivalry?

Various things can initiate a squabble between brothers and sisters. If you ask Dr. Mark Feinberg, host of Penn State University’s Siblings are Special Project, he’ll tell you that we’re all born with the capacity to be competitive and engage in conflict even at a very young age. This makes a lot of sense when you consider it from a biological survival perspective. When you’re not old enough to care for yourself, you’re competing for love, attention, food, and protection, which are all underlying reasons for sibling rivalry. But when there’s plenty of love and resources in a home, why do siblings still fight? Here are a few other reasons why your toddler and his little sister might be clashing.

Need for Structure

Structure is highly regulating for toddlers, so they may become anxious if they need more structure, or if routines are off. When a toddler doesn’t know what to expect, he can start to test boundaries with parents, caregivers, and siblings. It’s helpful to have clear expectations and limits, and stick to routines as much as possible.

Problems in the Hierarchy

You’ve probably read a million times that toddlers are like little sponges, absorbing everything that goes on around them. If there’s a conflict between parents and/or caregivers, they’ll notice it. When there’s tension in the hierarchy, siblings can feel the effects and will often mimic adult conflicts with each other.

Evolving Individual Needs and Behaviors

As your toddler and baby are growing, they’re developing their own individual identities and personalities, and expressing their own needs. More often than not, these developing needs and behaviors will naturally cause friction. Your toddler might start to become more possessive over his space, his toys, and your attention. These are all things that define who he is, so he might feel more threatened by his little sister playing with his favorite toy car or getting a bath before he does.

Tips for Managing Sibling Rivalries

Feinberg’s research shows that siblings can have a very strong effect on each other’s lives. In fact, a sibling’s influence can be just as powerful as a parent’s influence on friendships, romantic relationships, careers, emotional intelligence, and mental health. That’s why it’s worth it to strive for creating a positive and healthy relationship between them. Here are a few things that can help ease sibling tension:

Set time aside to be alone with each child. Even if it’s just for a few minutes each day, one-on-one time with each child can make them feel less threatened and more confident in the family dynamic.

Teach them the difference between equal and fair. Because of their different ages, they’ll have different routines, roles, and responsibilities. Just because something isn’t equal, doesn’t make it unfair. For instance, a younger toddler might be upset that her older brother gets to go to preschool while she stays at home. She’ll eventually understand that she’ll also get to go to preschool when she’s his age.

Be mindful about putting the burden on the older child. We may expect the older sibling to constantly “know better” and make him share everything with his baby sister. This can easily spark conflict and resentment. Have a few special toys in a special place that his sister can’t reach. It’s also important to instruct her to ask him for his permission before she takes a bite of his snack. Of course, this is always easier said than done! Patience is key for this one!

Praise them when they’re getting along well. When you notice that they’re sharing on their own and working out their differences in their own way, take time to praise them.

Above all, remind them that their relationship is special, and when they express love and compassion for each other, the whole family grows together.