First Impressions May Affect Your Mood More Than Previously Thought

An illustration of a girl looking at a book with many thoughts circling.

Verywell / Getty Images

Kay Takeaways

  • Your first experiences in a new situation may have a longer-term influence on your mood than recent ones, a study finds.
  • This challenges the common belief among experts that recent experiences most affect how a person feels at any given time.
  • The research, although in its early stages, could have implications for treatment and research in the future.

First impressions are thought to influence our overall perception of someone or something. Research has also helped coin the term primacy effect, which finds that we tend to remember the first information shared in a list better than the information shared later. 

But for emotions, it is commonly thought by experts that the most recent, rather than initial, experiences impact mood the most.

Hanna Keren, PhD, a postdoctoral fellow at the National Institute of Mental Health (NIMH) Mood Brain and Development Unit, and author on a study that challenges this view says it's time to reevaluate that.

"When learning a new environment, each experience provides us new information that we can compare against prior information," Keren tells Verywell. Following this logic, she says, first impressions can become what we compare following ones to, and "as a result, they can hold together emotional weight over time."

Shifting this focus could, Keren adds, inform treatment plans in clinical settings, as well as future research.

This June study was supported by NIMH and published in the eLife journal.

Back to the Beginning

As often happens, Keren says, she and her colleagues came across this study idea by accident.

They were studying large mood transitions using a game they developed and found that the classic computational model of mood did not fit the data as well as expected.

That's because that computational model was based on the idea that more recent experiences have a stronger effect on mood. 

"When we noticed that in all models, we always make the same known assumption—that mood is primarily affected by the most recent rewards," Keren says, "we started developing a variety of alternative mood models to test this assumption."

Next came a period of trial and error. Eventually, Keren and colleagues centered on a primacy model, which seemed to most accurately account for past participants' self-reported mood.

They also decided to test their primacy model on new participants with new mood self-reports. It worked like this: Recruited adults played an online gambling game, and received small monetary rewards when they scored well.

In another set of experiments, adolescents played a similar game. All players used a sliding scale to report their moods at several points throughout playtime. Importantly, researchers also collected data on depression, as the disorder can impact mood.

While analyzing the data from trials, researchers found that early events during the game had the greatest impact on self-reported mood for both adults and adolescents, regardless of a depression diagnosis.

Keren says she and her colleagues were surprised, and "actually, a model where earliest rewards during the experiment had the largest influence on mood fit the data better."

What This Means For You

Your mood may be more impacted by earlier experiences during an interaction than ones that occur later. Keeping this in mind may help you pinpoint why you may be feeling a certain way.

Why Do Earlier Experiences Impact Mood?

To explain why experiences that occur early in an interaction or game seem to affect our mood the most, Keren turns to examples in daily life.

"We can imagine the different feeling we’d have making an important mistake in a new job we just started, versus making the same mistake after we’ve been successfully working in that place for a while," she explains.

This positive-negative comparison idea could apply to social first impressions. Let's say you have a negative interaction upon first meeting your doctor. Your mood may be more likely to sour toward them in future check-ups.

To understand the neurological underpinnings, Keren and colleagues also recorded the brain activity of their participants.

As the game was being played, neuroimaging showed that earlier experiences seemed to "switch on" frontal brain regions that are associated with mood.

"We also found neural signals that might be involved in this stronger influence earlier events hold on mood," Keren says. So, initial moods may be encoded early on without changing as much as the situation could.

If you were doing badly at the beginning of the gamble, then, some later success might not feel so sweet.

What Does This Mean for Treatment and Research?

In both clinical and research settings, people and participants report their moods. Shifting focus away from most recent events may help to more accurately treat and reflect a person's mood.

"In the future, these findings could be applied," Keren says. For example, clinicians can tailor treatment sessions to focus more on the earlier experiences that happened during the patient’s day. At the same time, researchers can reconsider experimental designs that rely on mood reporting.

Until further research, there's no solid data for right now about whether that first impression will affect mood long-term.

"There are still more open questions to be addressed, such as what happens over longer time scales, or during other more realistic settings," Keren says.

2 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. American Psychological Association Dictionary of Psychology. First impression.

  2. Keren H, Zheng C, Jangraw D et al. Timing matters: The temporal representation of experience in subjective mood reports. doi:10.1101/815944

By Sarah Simon
Sarah Simon is a bilingual multimedia journalist with a degree in psychology. She has previously written for publications including The Daily Beast and Rantt Media.