Emotions in Childhood

About

Humans are exceptionally social and understanding others' emotions as well as regulating one’s own emotions are foundational skills that children acquire and continuously build across development to successfully navigate the social world. Emotions are an important element of nonverbal communication, in particular at an early age before children acquire the vocabulary to express how they themselves feel and to understand how others feel.

The goal of the EmoChi-project is to develop a knowledge-exchange hub to make research on emotional development accessible to children, parents, caretakers, and other stakeholders. We are looking to engage in a conversation about what it is we know about emotions in (early) childhood and how we can use this knowledge to improve children's social competence.

The content of this website was created by the research team of the Social Foundations Lab and it is continuously updated as we incorporate feedback from parents and children.

News and updates

We have been working together with Gameloft and Ferrero Int. to integrate the content of this website within a game which introduces children to the topic emotions. The launch of this game on both the Google Play Store and the Apple App store is scheduled for October 2024. We have co-designed the game with our partners to feature educational elements to encourage conversations between children and their parents about feelings and emotions in everyday life.   

 

What is an emotion

Emotions play a key role in our everyday lives. They influence how we interact with other people and how we navigate our (social) environment . For example, fear might prompt us to avoid danger, while happiness encourages social connection, and surprise might make us try and make sense of a situation. Despite their importance, and the attention they have received from different fields such as neuroscience, psychology and philosophy, it is difficult to define what an emotion is. Most researchers agree that emotions are complex psychological and physiological reactions to internal events (thoughts, imaginations) and external events (situations and context). Emotions can be characterized by:

• Subjective experiences → The feelings we have when we experience an emotion.
• Physiological responses → Sweating, heartbeat, and breathing which can activate or deactivate the body depending on the situation.
• Behavioural responses → This can include facial expressions and bodily movements

The development of emotions

Current research suggests that emotional understanding and perception develop significantly across childhood and into adulthood. Several factors have been found to play an important role. These include:

• The family environment: For example, children who grow up in families that express emotions tend to develop better emotion understanding skills.
• The child’s overall language development and conversations about emotions. For example, regular and open conversations about emotions within the family context have been found to enhance children’s emotional understanding (Ogren & Johnson, 2021)

As parents it is important to recognise that there are important differences between adults’ and children's recognition and understanding of emotions. Studies indicate that children, in their preschool years, begin with two broad emotion categories - "feels good" and "feels bad". With development and further experiences, children gradually acquire more specific emotion categories, and their understanding becomes more adult-like (Widen, 2013).

Positive emotions || Happiness

What is happiness?

Happiness, and joy, are considered positive emotions which are experienced as being pleasant and sometimes activating. Amongst the so-called universal emotions, happiness and joy are the most desirable. They do not only arise in response to doing or receiving something but also from a sense of connection between people or a sense of wellbeing (Messinger et al., 2019).

Children’s understanding of happiness develops gradually. By the age of five years, children understand what happiness means drawing from their own experiences of what felt ‘good’. Happiness was described as joy, love, feeling good, having fun, and just feeling really happy overall. Younger children found it difficult to explain the idea behind happiness. Children report feeling happy when they receive a new toy or played with friends. Explaining happiness for younger children is made easier by drawing on real-life examples (Hong et al., 2015).

One study explored how parents communicate emotions to children aged 12 to 24 months during a shared book-reading task. Infants provided labels for emotions around the age of 18 months. Parents used more emotion labels for happiness and sadness, while fewer for disgust. This suggests parental communication influences children’s emotional understanding. Children may label happiness earlier due to parents' frequent discussion of this emotion, highlighting the significance of early emotional communication in development (Ruba et al. 2022).

To investigate how specific and general vocabulary influence emotion understanding, researchers presented children between the ages of 4 to 9 years with vignettes representing different emotions, including happiness, and asked children to indicate how the protagonist in the vignette felt. Children who knew more emotion specific words (beyond their general vocabulary size) demonstrated better emotion recognition and understanding of emotion regulation strategies. This suggests that such vocabulary extends beyond general language skills in enhancing emotional comprehension (Streubel et al., 2020).

How is happiness expressed?

The most common ways people describe the sensation of happiness is feeling light or uplifted, energetic, buzzing or tingling, warm, or grounded. The facial expression most commonly associated with happiness is a smile. We can change our facial expressions to look as though we are smiling (even if we do not experience happiness). There is a specific smile, the so-called Duchenne-smile which is difficult to stage and is therefore considered to be a genuine expression of happiness (including the characteristic ‘crow's feet’).

Happiness can be expressed in the tone of voice and in our posture: Some states of enjoyment may be signaled with a sigh of content, a squeal of joy, excited exclamation or shout, or laughter. Posture changes can be upright or elevated. Children show elevated posture after helping others and after seeing others being. For children at 5 years of age, this expression of happiness is stronger when others are watching their helping behaviour (Hepach et al., 2023).

In one study, researchers focused on understanding children's happiness as a measure of their well-being. Happiness was explored in 6- to 8-year-olds through drawings, group interviews, and photos. Children drew, discussed, and took photos of things that made them happy. The themes which emerged revolved around instances of play and social interactions which significantly influenced children’s experience of happiness. By understanding what brings children joy, we gain insights into their overall well-being and can better support their happiness (Moore and Lynch, 2017).

What causes happiness?

Children’s relationship with their primary caregivers is a key factor influencing a child’s emotional development and thus their happiness. An example of this is the effect of caregiver’s emotion-based language. Parents more frequently use emotions labels for happiness compared to other emotions when describing pictures in a book to their children. This may explain why children are better at recognizing happiness compared to recognizing other emotions (Ruba et al., 2022). 

Family dynamics and positive emotions go hand-in-hand. In one study including families from Mexico, a culture which is places a strong emphasis on community, found that mothers who shared positive emotions in their interactions with their child reported lower levels of parenting stress and they reported fewer temperamental outbursts from the children in their daily lives (Lindsey, 2022).

Researchers examined how caregivers’ emotions and behaviors during interactions with their preschool children (3- to 5-year-olds) impact children's overall happiness. Caregivers' own expression of happiness, rather than their approach behaviors, were linked to children's expressed positive emotions. However, specific caregiver actions such as narrating and sharing emotions with their child correlated positively with children's own happiness. This highlights the importance of caregivers being emotionally responsive to children because this shapes children's experiences and expressed happiness (Hill et al. 2023).

Children express elevated happiness after sharing resources (such as cookies) with others. Five- year-old children were judged to look happier after sharing with others compared to when they themselves received a reward. This positive emotion was stronger after children themselves gave up a reward compared when then merely saw someone else receive a reward. In the literature this is referred to as the “warm-glow effect” (Aknin et al. 2012).

In one study, young children felt happiest when playing with their favourite toys, when spending time with loved ones, getting hugs when they needed them, unwrapping presents, visiting exciting places, enjoying their favourite meals, feeling cozy and relaxed, and accomplishing something they worked hard for. The study concluded that it is the ‘simple’ things which often result in children feeling happy (Hong et al., 2015).

One question researchers are interested in is how emotional expressivity and emotion regulation relate to children’s academic motivation, engagement, and overall achievement. Sixth graders (average age 10 years) who were motivated to do well at school and engagement were also judged to look happier. In particular hose children who were skilled at regulating their own emotions, negative and positive, showed higher academic motivation and higher academic achievement (Kwon et al. 2017).

Good to know

Alongside age differences, there are also cultural influences. For example in western cultures, which tend to be individualistic, happiness reflects a high level of positive affect and more of a sense of satisfaction. In American English, the concept of happiness has evolved to denote positive internal feelings. Happiness is subjective, characterized by heightened positive emotions, diminished negative emotions, and possibly a feeling of contentment or fulfillment. In Mandarin Chinese there are different words to express different states of happiness, such as ‘Gao Xing’ for subjective feelings and ‘Kauai Le’ for general character (Yang et al. 2021).

Awe is a positive emotion that, like surprise, arises from witnessing unexpected events. Similarly, it can elicit curiosity, encouraging learning, especially in young children (Colantonio & Bonawitz, 2018). Awe has also been linked to prosocial behaviour, such as sharing and charity (Stamkou et al., 2023). The expression of awe includes widening of the eyes, raised inner eyebrow, open and slightly dropped jaw and mouth, goosebumps, small forward movement of the head, and visible inhalation (Lucht et al., 2024).

Pride is a positive emotion but also a self-reflective emotion, that occurs following a relevant accomplishment (Peplak et al., 2023). Much research has investigated the development of pride in children, finding that pride can be recognised by children at the age of 4 years. The expression of pride includes a small smile, head titled slightly back, arms either raised above the head or placed on the hip, and a visibly expanded posture (Tracy et al., 2003).

Pride and happiness, though both positive emotions, can be distinguished by the fact that pride requires the individual to be and feel responsible for the positive event. Children progressively differentiate between these two emotions, a skill which matures between 9 and 11 years of age. Pride can also be derived from both self-achievement and altruistic behaviour (this is known as moral pride) and this form of pride develops later in development (Kornilaki & Chlouverakis, 2004).

In one study, researchers examined how different types of play, including pretend and physical play, predicted children's social and emotional skills over a period of two years. Younger children demonstrated lower emotional knowledge and regulation initially but improved over time. Sociodramatic play predicted better emotional expressiveness and regulation, while rough-and- tumble play predicted expressiveness and regulation, with gender differences observed in play preferences and emotional skills (Lindsey et al. 2013).

Negative Emotions || Fear

What is fear?

Fear, or fearfulness, is one of the so-called basic or universal emotions in response to perceived threats to our or others’ safety and well-fare. The experience and expression of fear is considered to serve important survival functions, for example to avoid physical or social harm but also to signal a need for help and to get attention from others.

How is fear expressed?

We often experience fear when we evaluate events to be unexpected, unpleasant, caused by something outside our control, and if we find ourselves unable to cope in response to the actual or imagined threat.

Fear is said to have a characteristic facial expression which includes widened eyes, stretched lips, and raised eyebrows (Ekman, 2003). However, there is considerable debate as to how universal (similar across cultures) these facial expressions are and how variable these expressions can be from person to person.

Experiencing fear is often described and characterized by heavy breathing, an increased heart rate, tightened neck muscles, increased pupil dilation, increased blood pressure, as well as increased skin conductance, e.g., ‘sweaty palms’ (Kreibig, 2010). Fearfulness can also be expressed in the tone of voice to include screams and gasps (Barrett, 2014; Sauter et al., 2010; Keltner et al., 2016).

What causes fear?

We can classify different types of fear (Arrindell, 1991): arising from social interactions or from shared environments, in response to actual or perceived harm, triggered by actual (or imagined) animals, or resulting from being in crowed spaces (i.e., agoraphobia).

Research found that the majority infants exhibit fear of strangers as they reach the end of their first year of life (Lewis and Brooks 1974).

According to evolutionary psychology, experiencing and expressing fear is adaptive and increases an individual’s chances of survival. However, most research seems to suggest that we are not born with innate fear responses. Instead, it is suggested that human are born with the capacity (including attentional biases) to develop fears of certain events (Thrasher & LoBue, 2016).

Good to know

Research on fear regulation has highlighted the advantage of attentional redirection. For example, children who were scared of blood being drawn using needles at the doctors, showed reduced fear when distracted by hand puppets (Oluç & Sarialioğlu, 2023). Caregivers can help reduce fear in children by redirecting their attention from the fear-evoking stimulus onto a comforting object or toy.

Studies found that children pay special attention to caregivers and modify their fear responses accordingly. When caregivers express fear and/or anxious behaviour, children mirror that response to that stimulus (de Rosnay et al., 2006). Similarly, children also pay attention to their caregiver’s protective behaviour, causing them to remain in a state of heightened alert (Buss & Kiel, 2011).

In an experimental paradigm where infants can cross a visual (non-real) cliff, it was found infants’ approach or avoidance behaviour on the visual cliff was influenced by their mothers’ emotional facial expressions (Klinnert et al., 1983).

Though there is some debate about the specific brain regions involved in fear processing, much research suggests primarily activation in the amygdala (Thomas et al., 2001), as well as other regions such as the anterior cingulate cortex (ACC) and the putamen.

Prosocial Emotions || kindness

What is Kindness?

Kindness describes the many behaviours and emotions that motivate people to help, comfort, and share with others. There is no single emotion of ‘kindness’ but we consider kind behaviours to be motivated by emotions which are felt in concern for others’ well-being. We feel empathy when we share the emotions of others and sympathy when we feel concern for others in need (instead of mirroring their emotions).

How is kindness expressed?

Feeling sympathy and concern for others has a distinct facial expression which is characterised by furrowed or raised eyebrows and a sad expression in the eyes. In addition, feeling sympathy and concern for others is often accompanied by a slowing of our heart rate which is a sign of increased attention to others (and their needs).

Children show concern for others from as early as 10 months of age. The extent to which children express concern is related to whether and how much children help others. Interestingly, it is the expression of concern and not mere attention to others which is related to children’s helping behaviour (Roth-Hanania et al., 2011).

Children can show concern in a variety of ways. Beyond expressing an emotion, feeling concern can be expressed in a variety of helping behaviours including handing others out-of-reach objects, comforting those who are hurt, and sharing resources with others (Dunfield, 2014).

We refer to helping as being motivated by kindness if it is accompanied by genuine concern for others’ well-being (as opposed to more selfish motivations). Kindness refers to motivations as much as emotions and children as young as 2 years show positive emotions if others’ needs are fulfilled (Aknin et al., 2012; Hepach et al., 2017).

What causes kindness?

We feel sympathy when we see others being hurt or when others are struggling or if they are in need of help. The feelings of kindness are about other people and not so much about ourselves. Being kind means that we want to make others feel better.

Kindness, and helping behaviour, are as much a part of human nature (our biology) as they are part of human culture (our upbringing and shared values). There is extensive research on the genetic basis of children’s concern for others (Zahn-Waxler et al., 1992) but there is an equal amount of research on the influence on sociialization on children’s kindness (Brownell et al., 2016). 

Kindness does not have a single cause but it is best described by emotions and motivations that are directed toward others’ needs. Children from as young as 9 months of age understand others’ needs, that is they can anticipate how others are best helped and it is both the understanding of others’ needs as well as children’s motor abilities which predicts children’s helping behaviour (Köster et al., 2015, 2019).

Good to know

There are many good reasons to be kind to others. Not only does it motivate us to make others feel better, but it can also make ourselves feel better about having acted kindly. In addition, our friends and families value kind behaviour and being kind can help us to make friends.

Comparative work suggests that some of the emotions and motivations underlying young children’s helping behaviour are shared with other primates. For example, chimpanzees help others in similar ways as do young children i.e., by providing access to food or by removing obstacles (Melis, 2018).

Studies on children’s helping behaviour often include clever paradigms to elicit helping and kindness in children. Examples include an adult, either the parent or another adult, accidentally bumping their knee on a table and subsequently expressing mild pain (Zahn-Waxler et al., 1992). In other studies, the adult pretends to be clumsy and accidentally drops objects or misplaces them (Warneken & Tomasello, 2006).

There is a lively debate in developmental science on how children’s kindness changes as they grow older. One milestone development is perspective taking and concern for one’s reputation. Children older than 4 years of age care about whether they are being watched while helping others, presumably to manage their good reputation in the eye of onlookers (Engelmann & Rapp, 2018).

Learning & Curiosity || Surprise 

What is surprise?

Surprise is an emotion that arises from a detected mismatch between expectation and experience (Barto et al., 2013; Ekman, 1994). The emotion is characterised by a sense of difficulty to explain how or why something happened (Foster & Keane, 2015; Maguire et al 2011), and is believed to motivate us to seek explanations and to make sense of the world.

What is the role of expectations and predictions for our lives? In recent years, findings suggest that the human brain is not entirely reliant upon external information (through vision, smell, touch etc.). Instead, memories of previous experiences and statistical learning are used to produce predictions about current and future states.

How is surprise expressed?

Surprise is assumed to be typically expressed by raised eyebrows, an open mouth, a gasp or intake of air, as well as dilation of the pupils (Ekman, 2003). From an evolutionary point of view, this behaviour is assumed to maximise the intake of information from the environment.

Research investigating young children’s ability to discriminate between different emotions has found that, for example, whilst happiness and sadness can be distinguished from a very early age, surprise recognition develops slightly later (Widen, 2013). Interestingly, fear and surprise expressions are often difficult to differentiate, which may be related to the number of similarities shared by facial patterns of the two emotions, including the raised inner and outer brow, the raised upper eyelid, and the open mouth (see also: Jack et al., 2016).

Surprise expressions develop gradually with age – whilst only 30% of 3.5-month-old infants show surprise, roughly 67% of 5.5-month-old infants display surprise. This may be encouraged by caregivers’ interactions with their children as some research has shown that mothers display exaggerated surprise expressions towards their infant (Reissland et al., 2002).

Cultural differences have been shown to exist for surprise causes and responses. For example, caretakers in East Asia have been found to express less surprise than people from Western cultures (Choi & Nisbett, 2000). This may be due to social norms, as Valenzuela et al., (20010) found that when the East Asian participants were asked to display less emotional control, they showed surprise responses similar to the American participants. 

What causes surprise?

Surprise is triggered by unexpected events. This can be for example hearing a loud sound suddenly next to you or seeing a person you know in a place you would not think they would be at. The key aspect here is the unexpectedness, as you cannot be surprised by something you know is going to happen.

Research often use surprise or surprise responses such as longer looking times or dilated pupils to measure what children know about the world. For example, experiments have been done which looked at children’s development of knowledge about intuitive physics (how do two objects behave when they clash with each other) or measuring if children form expectations based on probability (Doan et al., 2018).

Good to know: Surprise and Learning

Surprise is an emotion that has been linked to exploration and learning (Wentworth & Witryol, 1986). Research suggests a chain reaction in which a person’s expectations are defied, resulting in surprise, which leads to curiosity/confusion/interest, then exploration of the stimulus that triggered this process, which finally results in learning (Stahl & Feigenson, 2015).

Research has found that ‘desirable difficulties’, challenges that push children to seek knowledge, lead to more curious behavior which encourages memory and learning (Fandakova & Gruber, 2021). However, there is a possibility that presenting children with too much new and surprising information can cause children to feel overwhelmed, anxious and confused – as with everything, balance is important!

Research Team

Principal Investigator  Robert Hepach	Doctoral student Clemens v. Wulffen	Research Assistant Mary Astor
Research Intern  Zuha Murtaza	Research Intern  Ranya Hossain	Research Intern  Diana Signer
Research Intern Charlotte Dale

Artwork 

Illustrations provided by Allysa Adams

 www.allysaadamsillustration.com

References 

Development of emotions 

1. Ogren, M., & Johnson, S. P. (2021). Factors facilitating early emotion understanding development: Contributions to individual differences. Human development, 64(3), 108-118.
2. Widen, S. C. (2013). Children’s interpretation of facial expressions: The long path from valence-based to specific discrete categories. Emotion Review, 5(1), 72-77

Happiness 

1. Aknin, L. B., Hamlin, J. K., & Dunn, E. W. (2012). Giving leads to happiness in young children. PLoS one, 7(6), e39211.
2. Hepach, R., Engelmann, J. M., Herrmann, E., Gerdemann, S. C., & Tomasello, M. (2023). Evidence for a developmental shift in the motivation underlying helping in early childhood. Developmental Science, 26(1), e13253.
3. Hill, T., Mackinnon, S., & Coughlan, E. (2023). Crafting happiness from everyday life: personality, personal projects, basic psychological need satisfaction, and well-being. International Journal of Personality Psychology, 9, 47-60.
4. Hong, Y., Ra, Y., & Jang, H. (2015). A Study on Young Children's Perceptions and Experiences of Happiness. Asia-Pacific Journal of Research in Early Childhood Education, 9(1).
5. Kornilaki, E. N., & Chlouverakis, G. (2004). The situational antecedents of pride and happiness: Developmental and domain differences. British Journal of Developmental Psychology, 22(4), 605-619.
6. Kwon, K., Hanrahan, A. R., & Kupzyk, K. A. (2017). Emotional expressivity and emotion regulation: Relation to academic functioning among elementary school children. School Psychology Quarterly, 32(1), 75.
7. Lindsey, E. W. (2022). Shared positive emotion during parent-toddler play and parent and child well-being in Mexican origin families. Infant Behavior and Development, 67, 101706.
8. Lucht, A., & van Schie, H. T. (2024). The evolutionary function of awe: A review and integrated model of seven theoretical perspectives. Emotion Review, 16(1), 46-63.
9. Messinger, D., Mitsven, S. G., Ahn, Y. A., Prince, E. B., Sun, L., & Rivero-Fernández, C. (2019). Happiness and joy. Handbook of emotional development, 171-198.

Fear 

1. Arrindell, W. A., Pickersgill, M. J., Merckelbach, H., Ardon, A. M., & Cornet, F. C. (1991). Phobic    dimensions: III. Factor analytic approaches to the study of common phobic fears; an updated          review of findings obtained with adult subjects. Advances in behaviour research and therapy,          13(2), 73- 130.
2. Barrett, L. F. (2014). The conceptual act theory: A précis. Emotion review, 6(4), 292-297.
3. Brooks, J., & Lewis, M. (1974). Attachment behavior in thirteen-month-old, opposite-sex twins. Child Development, 243-247.
4. Buss, K. A., & Kiel, E. J. (2011). Do maternal protective behaviors alleviate toddlers’ fearful distress?.
5. International Journal of Behavioral Development, 35(2), 136-143.
6. De Rosnay, M., Cooper, P. J., Tsigaras, N., & Murray, L. (2006). Transmission of social anxiety from mother to infant: An experimental study using a social referencing paradigm. Behaviour research and therapy, 44(8), 1165-1175.
7. Ekman, P. (2003). Darwin, deception, and facial expression. Annals of the new York Academy of sciences, 1000(1), 205-221.
8. Keltner, D., Tracy, J., Sauter, D. A., Cordaro, D. C., & McNeil, G. (2016). Expression of emotion.
9. Handbook of emotions, 4, 467-482.
10.   Klinnert, M. D., Campos, J. J., Sorce, J. F., Emde, R. N., & Svejda, M. A. R. I. L. Y. N. (1983). Emotions as    behavior regulators: Social referencing in infancy. In Emotions in early development (pp. 57-86). Academic      Press.
11. Kreibig, S. D. (2010). Autonomic nervous system activity in emotion: A review. Biological psychology, 84(3), 394-421.
12. Oluç, T., & Sarialioğlu, A. (2023). The effect of a hand puppet-based therapeutic play for preschool children on the fear and pain associated with blood collection procedure. Journal of Pediatric Nursing, 72, e80-e86.
13. Sauter, D. A., Eisner, F., Ekman, P., & Scott, S. K. (2010). Cross-cultural recognition of basic emotions through nonverbal emotional vocalizations. Proceedings of the National Academy of Sciences, 107(6), 2408-2412.
14. Thomas, K. M., Drevets, W. C., Dahl, R. E., Ryan, N. D., Birmaher, B., Eccard, C. H., ... & Casey, B. J. (2001). Amygdala response to fearful faces in anxious and depressed children. Archives of general psychiatry, 58(11), 1057-1063.
15. Thrasher, C., & LoBue, V. (2016). Do infants find snakes aversive? Infants’ physiological responses to “fear-relevant” stimuli. Journal of experimental child psychology, 142, 382-390.

Kindness

1. Aknin, L. B., Hamlin, J. K., & Dunn, E. W. (2012). Giving leads to happiness in young children. PLoS one, 7(6), e39211.
2. Brownell, C. A., & Early Social Development Research Lab. (2016). Prosocial behavior in infancy: The role of socialization. Child Development Perspectives, 10(4), 222-227.
3. Dunfield, K. A. (2014). A construct divided: Prosocial behavior as helping, sharing, and comforting subtypes. Frontiers in psychology, 5, 958.
4. Engelmann, J. M., & Rapp, D. J. (2018). The influence of reputational concerns on children's prosociality. Current Opinion in Psychology, 20, 92-95.
5. Hepach, R., Vaish, A., & Tomasello, M. (2017). The fulfillment of others’ needs elevates children’s body posture. Developmental Psychology, 53(1), 100.
6. Köster, M., Ohmer, X., Nguyen, T. D., & Kärtner, J. (2016). Infants understand others’ needs. Psychological science, 27(4), 542-548.
7. Köster, M., Itakura, S., Omori, M., & Kärtner, J. (2019). From understanding others' needs to prosocial action: Motor and social abilities promote infants' helping. Developmental science, 22(6), e12804.
8. Melis, A. P. (2018). The evolutionary roots of prosociality: the case of instrumental helping. Current Opinion in Psychology, 20, 82-86.
9. Roth-Hanania, R., Davidov, M., & Zahn-Waxler, C. (2011). Empathy development from 8 to 16 months: Early signs of concern for others. Infant Behavior and Development, 34(3), 447-458.
10. Warneken, F., & Tomasello, M. (2006). Altruistic helping in human infants and young chimpanzees. science, 311(5765), 1301-1303.
11. Zahn-Waxler, C., Radke-Yarrow, M., Wagner, E., & Chapman, M. (1992). Development of concern for others. Developmental psychology, 28(1), 126.

Surprise 

1. Barto, A., Mirolli, M., & Baldassarre, G. (2013). Novelty or surprise?. Frontiers in psychology, 4, 907. Ekman, 1994 Doan, T., Friedman, O., & Denison, S. (2018). Beyond belief: The probability-based notion of surprise in children. Emotion, 18(8), 1163.
2. Ekman, P. (2003). Darwin, deception, and facial expression. Annals of the new York Academy of sciences, 1000(1), 205-221. Widen, 2013
3. Foster, M. I., & Keane, M. T. (2015). Why some surprises are more surprising than others: Surprise as a metacognitive sense of explanatory difficulty. Cognitive psychology, 81, 74-116. Maguire et al 2011
4. Fandakova, Y., & Gruber, M. J. (2021). States of curiosity and interest enhance memory differently in adolescents and in children. Developmental Science, 24(1), e13005.
5. Jack, R. E., Sun, W., Delis, I., Garrod, O. G., & Schyns, P. G. (2016). Four not six: Revealing culturally common facial expressions of emotion. Journal of Experimental Psychology: General, 145(6), 708.
6. Reissland, N., Shepherd, J., & Cowie, L. (2002). The melody of surprise: Maternal surprise vocalizations during play with her infant. Infant and Child Development: An International Journal of Research and Practice, 11(3), 271-278. 
7. Stahl, A. E., & Feigenson, L. (2015). Observing the unexpected enhances infants’ learning and exploration. Science, 348(6230), 91-94.
8. Valenzuela, A., Mellers, B., & Strebel, J. (2010). Pleasurable surprises: A cross-cultural study of consumer responses to unexpected incentives. Journal of Consumer Research, 36(5), 792-805.