teen siblings sit outside

Why Did One of My Children Develop Problems When the Other Didn’t?

Parents with more than one child understand that each of their kids are different, and that these differences can have an impact during the teen years – but many parents don’t fully understand how their various experiences can combine to influence long-term well-being and developmental outcomes, including those related to mental health.

Despite the clear understanding that each child is unique, parents often have difficulty with the fact that one child may develop mental health issues as they grow up, when the other – or others – may not develop any issues at all. A new study sheds light on this phenomenon, and identifies a factor that has the power to predict some developmental outcomes during young adulthood:

Perceived levels of household chaos.

Experts on family dynamics define household chaos as “the level of disorganization or environmental confusion children are exposed to in their family homes.” They identify the following components common to households considered chaotic:

  • Lack of family routines
  • Absence of predictability
  • Lack of daily structure
  • Fast pace of family life

Research shows children who grow up in chaotic households have an increased risk of negative developmental consequences, including:

  • Impaired social-emotional functioning
  • Low educational achievement
  • Behavioral problems

The new study – Adolescents’ Perceptions of Household Chaos Predict Their Adult Mental Health: A Twin-Difference Longitudinal Cohort Study – is the first to examine the impact of exposure to household chaos on developmental outcomes during adulthood. The research team sought answers to two basic questions:

Did adolescents who perceived their family homes as more chaotic experience negative developmental outcomes in adulthood than those who didn’t?
Did adolescents whose parents reported greater household chaos experience negative developmental outcomes in young adulthood than those whose parents didn’t?

The answers to these questions are instructive. They can help us better understand how same-age, same-sex, fraternal and identical twins from the same home environment experience different developmental outcomes in early adulthood.

Perceived Household Chaos During Teen Years and Mental Health: How the Study Worked

To measure perceived levels of household chaos, participants completed an established psychological tool called the Confusion, Hubbub, and Order Scale (CHAOS). Parents and twin pairs competed the CHAOS test when twins were 9, 12, 14, and 16 years old.

The CHAOS test includes statements like:

I have a regular bedtime routine.

You can’t hear yourself think in our home.

It’s a real zoo in our home.

We are usually able to stay on top of things.

There is usually a television turned on somewhere in our home.

The atmosphere in our house is calm.

Parents and twins rated statements as not true, quite true, or very true, which researchers used to determine a CHAOS score. Then, when twin pairs reached age 23, the twins answered another series of questionnaires to gauge the following:

  • Educational attainment
  • Occupational status
  • Earnings
  • Substance use:
    • Alcohol
    • Cannabis
  • Sexual risk taking
  • Conflict with the law
  • Mental health:

Let’s take a look at what they learned.

The Results: Impact of Perceived Levels of Household Chaos on Developmental Outcomes

The findings from this study are surprisingly specific. In fact, it’s more efficient to report what didn’t have a statistically significant impact on developmental outcomes between twins before reporting what did. Here’s what the research team observed.

  • Perceived household chaos by children/teens at ages 9, 12, or 14 did not have a statistically significant impact on differences between twins for the following adult developmental outcomes:
    • Educational attainment
    • Occupational status
    • Earnings
    • Substance use
    • Sexual risk taking
    • Conflict with the law
  • Perceived household chaos by parents at ages 9, 12, 14, or 16 did not have a statistically significant impact on differences between twins for the following adult developmental outcomes:
    • Educational attainment
    • Occupational status
    • Earnings
    • Substance use
    • Sexual risk taking
    • Conflict with the law

Now let’s look at what did have a statistically significant impact on developmental outcomes between twins.

  • Perceived household chaos by children/teens at age 16 predicted differences between twins in the following areas at age 23:
    • Depression
    • Self-control
    • Anxiety
    • Antisocial behavior
    • Aggression
    • Alcohol use

In addition, the researcher observed that parent reports of household chaos did predict some outcomes that were not related to mental health, such as educational attainment, their predictions did not differ from the subjective perceptions of household chaos reported by the child/teen twin pairs. What this means is that the perceived, subjective experience of the child/teen has significantly more predictive power than the perceptions reported by parents.

How Do We Interpret These Results?

In an interview published online, Dr. Sophie Von Stumm of the University of York, a lead author on the study, describes the results:

“Siblings who perceived the household as more chaotic than their brothers or sisters reported poorer mental health outcomes in young adulthood. This association was evident from adolescence onwards, confirming theories that the onset of mental health issues likely is during teenage years “

That begs the next question: how can twins report drastically different default conditions in their home environment?

One the one hand, it’s easy to see an environment in black and white terms. It’s either chaotic or it’s not. It’s either loud or it’s not. There are either consistent bedtime routines or there aren’t.

Right?

Right – but objective fact/reality is not the salient factor. The salient factor is individual, subjective perception.

That begs yet another question: how can twins develop such drastically different perceptions of their home environment?

Dr. Sophie Von Stumm explains:

“It is possible that children who experience more adverse events in early life than their siblings, like suffering an injury or being excluded from school, develop a heightened sensitivity to household chaos that then has long-term effects on their mental health.”

That explanation works. We know that two people can be present for the same thing and have completely different experiences. Take walking in the rain, for instance. When asked, “How was your walk?” One person might answer, “Amazing! It rained and we got soaked.” Another might answer, “Awful! It rained and we got soaked.”

Teen and Young Adult Mental Health: The Impact of Adverse Events on Perception

Now consider a teen twin who experiences an adverse event their twin doesn’t. It may happen at school, at sports practice, an extracurricular club, a family event, or somewhere else. The event may change them and how they see the world, and that change may influence how they perceive the home environment.

For the twin with the adverse experience, having a TV on all the time or missing a bedtime routine or two may qualify as chaos. In contrast, the other twin might shrug it off, and see those circumstances as part of their typical, stable routine. Sure, there’s some variation, but for them it’s not chaotic: overall they see their home life as stable For the other twin, the noise and the lack of routine hits differently: overall they see their home life as chaotic.

According to this new research, that’s what can make a difference: the subjective perception of chaos.

This gives us another angle to pursue when we’re working with adolescents and young adults. When performing a psychiatric assessment, we can ask questions about the level of chaos they perceive – or perceived – in their home during childhood and adolescence, with a focus on events and perceptions around age 16.

For treatment professionals working with teens, this information can inform the type and manner of support they offer, and the same is true for treatment professionals working with young adults. They can use this information to help resolve issues from the past.

In both cases, the information is important. It can help psychiatrists, therapists, and counselors tailor treatment to meet the circumstances unique to each patient, based on their lived experience as individuals, separate and distinct from anyone else. We know from experience that one size does not fit all, and the better we can match treatment to specific needs, outcomes improve.