Common sense assumes that making consumption decisions at different times of the day has no impact on the decision. Marketers know that daily routines and seasonality cycles have an impact on the creation of demand, but they largely assume that consumer decision-making will not change between morning and evening. However, much research shows that the time of the day affects how consumers make decisions. Two factors seem to affect consumers at different times of the day: sleep deprivation and circadian cycles. Here, we will answer some questions about time effects in consumer decisions:

  • What affects consumers’ decisions at different times of the day?
  • How do they differ the decisions made at different times of the day?
  • How can marketers tailor their activities on time of the day?
  • Why time of the day is important for consumer segmentation?


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Circadian cycles and chronotypes.

As we know a day is made of 24 hours, and depending on where you are on the planet, some of these hours will be daytime and some nighttime. As humans evolved, their brain has interiorized the 24-hour cycle of day/night with the so-called circadian cycles. The brain reacts to light affecting the hormones that are released during the day, usually making people more alert and fresher when they see the light in the morning. After sunset, the brain releases other hormones, that make people more likely to be calm and sleepy. This description is just a simplification of complex hormonal reactions that light and darkness have on our physiology but describes how sleep and alert times are deep physiological factors and not just societal constructions.

Morning birds and night owls

People differ in the hormonal patterns of the 24-hour cycle of wake/sleep (i.e., they have different chronotypes). On one side, the majority of people are more alert at the beginning of the day and more tired at the end of the day (i.e., “morning birds”). On the other side, some people are tired in the morning, but they are very alert in the evening (i.e., “night owls”). Having to do a cognitively heavy activity during the wrong time of the day, affects how people perform on that activity. For example, if an early bird (the most prevalent type) is required to work late in the evening, they will be very tired and will make much worse decisions during the task. The opposite is true for night owls: they will make worse decisions in the morning because they will be more tired. The prevalence of morning birds over night owls explains why the conventional working times are from early morning to late afternoon, and not from late morning to late evening.



The second factor in this area is sleepiness. Sleepiness is a state of deprivation from sleep that makes people cognitively tired. People differ for the time they need to sleep every day (the average is around 8 hours), but everybody needs some sleep. The more time consumers remain without sleep, the more they will feel sleepy and tired and will have fewer cognitive resources (similarly to early birds working late at night). Sleepiness and chronotype are independent constructs: while chronotypes describe the relation between light and hormones, after some time without sleeping, both morning birds and night owls will feel the need to go to sleep and will suffer the negative effects of sleep deprivation.


Consequences for consumer behavior

  • Sleepiness and time of the day drive variety seeking. In a previous article, we have seen that people have higher variety seeking in the evening than in the morning: the increased arousal that people have during the day makes people looking for more variety in the evening. However, when people are sleep deprived (independently from the time of the day) they are in a very low arousal state, which is also very aversive for people. In this “low” situation, consumers need some external source of arousal to maintain wakefulness. Research shows that consumers seek variety to have the extra arousal that they are looking for. In that way, choosing variety becomes a way to stay awake.
  • Making a choice and then sleeping increases subsequent satisfaction about the choice. Studies have shown that if people sleep after having made a choice, then they are happier about the choice they made. The feeling of “having slept on it,” makes people perceive a higher distance from the choice. With more distance, the aversive effects experienced during the decision-making process are further away, and people become happier about the decision.
  • Sleep deprivation has the important consequences of decreasing people’s cognitive abilities. It decreases learning, working memory capacity and make people do poorer decisions. The effect on decision-making is particularly important. With sleepiness, people have lower self-control, are more susceptible to temptation, and are more shortsighted. Many bad decisions are made at late night because this is the time of the day where people are more likely to suffer from no sleep.
  • People have higher morality in the morning and lower in the evening. As for any decision-making, also moral decisions are affected by cognitive abilities. Studies show that people are more likely to make straight moral decisions in the morning than in the evening. This is because people have more cognitive resources in the morning than in the evening. Later studies have shown that the morning morality theory is true for the majority of “early birds”, but for the “night owls,” the effect is reversed. Night owls are more likely to make bad moral decisions in the morning, but they make good moral decisions in the evening. Finally, a study showed that sleep deprivation similarly affects moral decision-making. Consumers that had mild sleep deprivation (18+ hours without sleeping) were more likely to make wrong moral decisions than people that had plenty of recent sleep.


Consequences for marketers

  • Tempting products are more effective in the evening than in the morning. In a study, people were more likely to read a New York Times article than a Vogue article in the morning, but the opposite was true for the evening. The majority of early birds are more likely to fall into temptation in the evening than in the morning. If your product is tempting (or if you can make it look like a temptation), prefer late evening touchpoints. For example, social media managers or a tv content schedulers may want to schedule entertainment in the evening and news in the morning.
  • Cognitive information works in the morning, but emotional appeals work in the evening. In the morning people are more likely to look for cognitively heavy content, so they can be addressed with more heavy and rich information. However, in the evening marketers should prefer emotional appeals, and lower as much as possible the cognitive content of their messages. Emotional appeals are important in general, but they are particularly important in the evening.
  • Use chronotypes in your segmentation. Online data can be used to see whether people prefer to wake up in the early or late morning, and they can see when the peak of online activity is. This information can be used to distinguish early birds from night owls. With this information, marketers can tailor the activities for the level of cognitive abilities that consumers have at each time of the day.
  • Consumer cheating is more frequent in the late evening and at night. There are times where companies are facing consumer cheating (e.g., shoplifting, exploitative eCommerce returns, etc.). With big data, companies can add the time of the day to predict when cheating is more likely to happen. Both traditional algorithms and machine learning can pick up this information and make more accurate predictions, allocating more resources in those times where cheating is more likely to happen.


Take home message

The majority of consumers are more awake in the morning than in the evening. In the morning consumers look for more cognitively heavy activities and are acting more morally; in the evening consumers process information emotionally, are more susceptible to temptations, are less morally strict, make worse decisions, and want more variety. Some of these effects can differ for the so-called “night owls,” that are more awake in the evening.


Monthly Consumer Discoveries is a Monthly newsletter that brings you the most interesting updates in consumer behavior research.




Are you an early bird or a night owl? The question is not just for entertainment purposes. Knowing your chronotype will tell you when your best hours of the day are. You can use your best hours to do your most important work and your worse hours to do the least important work (e.g., clerical work). Knowing your chronotype will make you more efficient during your daily routine.



Gunia, B. C., Barnes, C. M., & Sah, S. (2014). The morality of larks and owls: Unethical behavior depends on chronotype as well as time of day. Psychological science25(12), 2272-2274.

Kouchaki, M., & Smith, I. H. (2014). The morning morality effect: The influence of time of day on unethical behavior. Psychological science25(1), 95-102.

Barber, L. K., & Budnick, C. J. (2016). Sleep and unethical behavior. Work and sleep: Research insights for the workplace, 125-146.

Karmarkar, U. R., Shiv, B., & Spencer, R. M. (2017). Should you Sleep on it? The Effects of Overnight Sleep on Subjective Preference‐based Choice. Journal of Behavioral Decision Making30(1), 70-79.

Pace‐Schott, E. F., Nave, G., Morgan, A., & Spencer, R. M. (2012). Sleep‐dependent modulation of affectively guided decision‐making. Journal of sleep research21(1), 30-39.




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