Half-Sibling Resentment: Causes And How To Deal With It

If you've watched and followed TV dramas with big, extended families, you most likely have an idea of half-sibling relationships. You have witnessed the character's constant power struggle and the quest for parental acceptance and validation until the last episode. Such are the recurring themes among the full- and half-siblings.

What’s the difference between step-siblings and half-siblings?

The distinction lies ultimately in the way the siblings are related. Half-siblings have one biological parent in common, while step-siblings are related only by union of their parents and these are the children from previous marriages or past relationships.

What triggers sibling resentment?

On Frontiers’ website, a research article touching on conflicts between full and half-siblings tells about the fundamental biological theories on sibling competition: kin selection theory and parent-offspring selection theory. These theories are thought to be behind half-sibling resentment.

Kin selection theory

It is believed that “kin selection theory predicts that individuals are more likely to provide help and to invest resources in genetically closer kin compared to more distantly related kin and to non-kin. Consequently, conflicts between family members can be assumed to decrease as genetic relatedness is higher.”

How equally parents are inclined to divide resources among their offspring will greatly impact resource scarcity or abundance, and thereby increase sibling competition.

Parent–offspring conflict theory

Meanwhile, the parent–offspring conflict theory states that “a parent’s evolutionarily optimal level of investment in any given offspring is determined by the relative benefits of investing in that offspring compared to investing in other current and future offspring.”

Meaning to say, the amount of resources available and how equally parents are inclined to divide them among their offspring will greatly impact resource scarcity or abundance, and thereby increase sibling competition.

In addition, “...there will be less conflict among those who are biologically related than among those who are less biologically or non-biologically related. Children are only 25% genetically related to each half-sibling, thus resulting in even greater divergence in expectations for and receipt of parental investment, resulting in higher levels of parent-child conflict in families containing half-siblings," says Kate Harcourt in her study on examining family structure and half-sibling influence on adolescent well-being.

She adds, "Thus, it is expected that the introduction of a younger half-sibling will result in higher levels of conflict between extant children and their biological parent than will the introduction of a younger full sibling,” 

Overall, what can cause half-sibling resentment are kinship according to kin selection theory, unequal parental treatment and investment, along with other demographic, emotional, and socioeconomic factors that highlight the parent-offspring conflict theory.

How to deal with half-sibling resentment

Whether half-siblings or full-siblings, conflict will never cease to exist. It is a constant reminder that we all have knowledge, views, experiences, and thought processes that are unique to each family member.

But when push comes to shove, here are five tips for parents to manage half-sibling resentment:

1. Avoid taking sides.

Give them the chance to resolve issues on their own unless you witnessed one child hurting another without obvious provocation. If the situation warrants a referee, encourage your kids to take part in conflict resolution. Ask, “Since nobody wants to share the tablet, I just might as well keep it. Would you share and decide to take turns or should I just put the tablet away?”

2. Offer a solution that’s beneficial to everyone.

Teach your kids the value of respect and compromise. Show them that while it is normal to get upset, it is not okay to resort to violence, name-calling, and swearing. Teach them what empathy looks like by putting themselves in their siblings’ shoes.

3. Avoid playing favorites.

Kids will notice if you always rush to rescue your youngest or the child who is named after you. Playing favorites will only intensify sibling resentment if one feels that the other child is favored over him/her. Provide individualized support and attention to each of your child's needs and interests.

4. Embrace the blended family dynamics.

Avoid comparing children and mentioning how different your child is from a half-sibling. Model the behavior you want to elicit from your children as they communicate and co-exist with half-siblings. Make sure that you embody acceptance and forgiveness so that your children will not walk on eggshells with you around nor compel them to act in your defense.

5. Keep the narrative plain and simple.

Since you have decided that you will commit to a blended family setup, make it known that a brother is a brother and a sister is a sister, full stop.

No need to emphasize the nature of how they came to be as their siblings. The term “half” can bring about various negative emotions and memories like losing the biological parent, nuclear family crumbling down, failed marriage, social status insult, trauma, and identity crisis.

At the end of the day, what matters is not the term that compares one sibling to another but that they all have genuine respect for each other while living their lives to the fullest.

Children have feelings, too

Transitioning to a new family life and culture, with additional family member/s in tow, can take a toll on our children’s young minds. We must show care and concern about how they feel with all the major life changes going on around them.

According to the book, Parenting with Love and Logic by Dr. Foster Cline and Jim Fay, we need to help our children solve their difficulties by identifying their feelings: “Were they feeling mad, sad, frustrated, left out, or something different? Why did they resort to angry words, rather than playing nice?”

The book adds, “First, they need to identify their feelings, and second, they need to identify different ways of handling them.”

Need a guide to a happy blended family? Click here.