Health is built on habits: eating well, exercising, sleeping enough, staying hydrated, taking medication as prescribed. Equally, it is undermined by unhealthy routines: skipping sleep, relying on processed foods, neglecting activity or overindulging in alcohol and sugar. These behaviours accumulate silently over days and weeks, shaping wellbeing and risk of disease.

Yet how people remember and evaluate their habits is rarely a neutral record of what actually happened. Working memory is the fragile system through which we recall and interpret past behaviour and it is systematically biased. Instead of accurately tracking every snack, workout or late night, memory compresses and distorts. Recent of vivid episodes dominate. Routine lapses are forgotten. A single extreme event enchors the whole judgement. Mood colours recall and people take shortcuts when asked to summarise.

This article explores how core working memory biases shape the way people perceive their healthy and unhealthy behaviours. The distortions matter because self-perception drives motivation: people act on what they believe their habits have been, not on the full reality.

Recency Bias: The Fresh Start Illusion

Recency bias makes the most recent events weigh disproportionately in memory.

• Health behaviours: someone who exercised twice this week feels “back on track”, even if the previous month was sedentary. A few salads create the impression of a healthy diet, overshadowing weeks of processed food. This fuels the common “fresh start illusion”. This is the belief that recent improvements define the overall pattern.

• Unhealthy behaviours: A recent lapse looms large. After one night of overeating or heavy drinking, people may feel that they are “failing” overall, despite longer-term stability. Conversely, if the last few days have been abstinent, a person may downplay the accumulated risks of the month.

Recency bias means people overinterpret their latest behaviour, oscillating between false optimism and undue discouragement.

Salience and Vividness: Memorable Episodes as Anchors

Working memory privileges vivid and unusual episodes.

• Healthy behaviours: A dramatic success, completing a 10k run, reaching a weight milestone or finishing a tough gym session, overshadows the more routine, less memorable days. People define themselves as “fit” based on peak experiences rather than consistency.

• Unhealthy behaviours: one vivid lapse, such as a weekend binge or a severe hangover, becomes the references point for self-judgement. For some, this inflates guilt and the sense of being unhealthy; for others, the memory fades quickly, allowing minimisation of more routine but less vivid unhealthy habits, like nightly snacking or skipped sleep.

Salience distorts evaluation by making the memorable stand in for the typical.

Mood-Congruent Recall and Current State Bias

What we recall depends on how we feel at the moment of recall.

• Healthy behaviours: In a positive mood, people remember their successes: the good meals, the workouts, the early nights. They see themselves as disciplined and motivated. In a negative mood, failures come to mind: the skipped runs, the late-night snacking, the times they “fell off the wagon”. The same history looks different depending on the lens of the moment.

• Unhealthy behaviours: Current fatigue makes past lapses easier to recall (“I never sleep enough”), reinforcing negative self-perceptions. Conversely, when feeling energised, people may underplay past unhealthy behaviours and exaggerate their positive habits.

Mood-congruence creates volatility in self-assessment: behaviours appear better or worse depending on current emotional states, not just historical facts.

Averaging and Neglect of Variability

When summarising across time, people compress patterns into vague averages.

• Healthy behaviours: A month of 20 days of healthy eating and 10 days of indulgence is remembered as “I eat healthy sometimes”. The variability, i.e. of long streaks of good behaviour punctuated by lapses, is smoothed into a bland midpoint.

• Unhealthy behaviours: Binge-abstinence cycles are averaged into “occasional use” or “moderate drinking”, masking concentrated bursts of unhealthy activity. The peaks that drive health risk disappear into an “average” that sounds stable.

This flattening of variability undermines self-awareness. People believe their habits are steadier than they are, making both unhealthy streaks and genuine progress harder to recognise.

Interference and Overlap: When Habits Blur

Working memory struggles when similar items compete, creating interference.

• Healthy behaviours: Routine activity like walking, chores or light stretching blurs with formal exercise. People may count housework as a workout or undercount it entirely, leading to inconsistent self-assessment.

• Unhealthy behaviours: Overlapping categories like snacking versus meals, or sugary drinks versus desserts, become hard to track. Small unhealthy act blur together and the total is underestimated.

Overlap creates “fuzzy accounting” where categories of behaviour interfere with each other, leaving the person uncertain what to count.

Anchoring to Extremes: Peaks as Identity

Extreme episodes act as anchors, shaping overall judgement.

• Healthy behaviours: A single week of perfect adherence (exercise every day, strict diet, full sleep) becomes the benchmark, inflating self-image as “healthy”, even if unsustainable.

• Unhealthy behaviours: A single extreme lapse, such as a week of holiday indulgence, can anchor self-perception as “bad with food” or “unable to control myself”, even if baseline is moderate.

Anchoring makes the exceptional define the whole, for better or worse.

Omission: The Invisible Everyday

Because working memory is limited, routine low-salience events drop out of recall.

• Healthy behaviours: small, positive acts, choosing water over soda, taking the stairs, sleeping an extra hour, are forgotten, leaving people to underestimate their healthy routines.

• Unhealthy behaviours: mild but frequent lapses, late-night scrolling that cuts into sleep, second helps, sugary snacks, are omitted. Only dramatic episodes are remembered. The cumulative impact of small unhealthy behaviours goes unrecognised.

Omission biases evaluation toward the dramatic, neglecting the incremental habits that matter most.

Satisficing and Cognitive Shortcuts

When reflecting on behaviour is too effortful, people simply:

• Healthy behaviours: people default to broad labels, such as “I’m pretty healthy”, without tracking details. Shortcuts like “I eat vegetables most days” replace accurate recall of frequency.

• Unhealthy behaviours: Similarly, people downplay with shortcuts like “I only drink socially” or “I snack sometimes”, even if true patterns are more frequent.

Satisficing reduces accuracy, encouraging vague generalisations over specific recall.

Social Desirability and Self-Schema

Finally, memory is filtered by motivation and identity.

• Healthy behaviours: people who see themselves as disciplined recall evidence to support that identity, remembering the gym sessions but forgetting the skipped days. They present a self-schema of “being healthy” even if behaviour is inconsistent.

• Unhealthy behaviours: Underreporting or downplaying unhealthy habits because of stigma or guilt. A smoker may recall fewer cigarettes than actually smoked, or a night drink may frame their intake as lighter than reality.

Here, memory is not just distorted by capacity limits but by the desire to appear consistent with one’s values or identity.

Pulling It Together

When applied to healthy and unhealthy behaviours, the pattern of biases is clear:

• Healthy behaviours are inflated. People recall dramatic successes, omit small lapses and anchor to peak adherence, building a self-image of being healthier than they are.

• Unhealthy behaviours are minimised. Frequent but routine lapses are omitted; binge-abstinence cycles are averaged into misleading moderation; and social desirability pressures encourage downplaying.

The combination leads to systematic optimism: people perceive themselves as healthier, more disciplined and less at risk than their true habits warrant. At the same time, vivid lapses can occasionally distort in the opposite direction, producing guilt or discouragement.

Implications for Behaviour Change

Understanding these biases matters because motivation depends on perception. If memory makes people overestimate their healthy behaviour and underestimate their unhealthy habits, they see little need for change. Conversely, if one vivid lapse anchors judgement, they may feel demoralised and abandon efforts altogether.

For behaviour change interventions, the lesson is clear:

• Externalise memory. Tools like food diaries, step counters and sleep trackers reduce reliance on biased recall.

• Highlight patterns and not averages. Visualisations that show variability (good streaks, bad streaks) counteract averaging bias.

• Make the invisible visible. Smal routine habits, both positive and negative, should be surfaced, so they are not lost to omissions.

• Address mood and self-schema. Encourage reflection across different emotional states and frame identity around progress rather than perfection.

By designing supports that take working memory’s limits seriously, we can help people build a more accurate self-perception. This would be one that motivates sustainable healthy habits and reduces unhealthy ones.

Conclusion

Healthy and unhealth behaviours are remembered through the distorting lens of working memory. Recency, salience, mood, averaging, interference, anchoring, omission, satisficing and self-schema biases all shape recall. The net effect is a filtered self-narrative: people think are healthier and less unhealthy than they really are, with occasional distortions in the opposite direction when vivid lapses dominate.

These biases do not mean people are irrational or deceptive. They reflect the way human memory compresses and simplifies. If we want to promote real change, we must design interventions that make habits visible, highlight variability and support honest self-reflection. Only then can the story people tell themselves about their health align more closely with the reality of their behaviours.

Thank you for reading,

Mark Gibson, Clermont-Ferrand, France

Nur Ferrante Morales, Ávila, Spain

September 2025