Emotional and Social Development During Infancy

What you’ll learn to do: explain emotional and social development during infancy

Two infants lying on their stomachs looking at each other
Psychosocial development occurs as children form relationships, interact with others, and understand and manage their feelings. In emotional and social development, forming healthy attachments is very important and is the major social milestone of infancy. Attachment is a long-standing connection or bond with others. Developmental psychologists are interested in how infants reach this milestone. They ask such questions as: how do parent and infant attachment bonds form? How does neglect affect these bonds? What accounts for children’s attachment differences?

Learning Outcomes

  • Describe emotional development and self-awareness during infancy
  • Contrast styles of attachment
  • Describe temperament and the goodness-of-fit model
  • Use Erikson’s theory to characterize psychosocial development during infancy

Emotional Development and Attachment

Emotional Development

At birth, infants exhibit two emotional responses: attraction and withdrawal. They show attraction to pleasant situations that bring comfort, stimulation, and pleasure. And they withdraw from unpleasant stimulation such as bitter flavors or physical discomfort. At around two months, infants exhibit social engagement in the form of social smiling as they respond with smiles to those who engage their positive attention. Pleasure is expressed as laughter at 3 to 5 months of age, and displeasure becomes more specific to fear, sadness, or anger (usually triggered by frustration) between ages 6 and 8 months. Where anger is a healthy response to frustration, sadness, which appears in the first months as well, usually indicates withdrawal (Thiam et al., 2017). [1]

As reviewed above, infants progress from reactive pain and pleasure to complex patterns of socioemotional awareness, which is a transition from basic instincts to learned responses. Fear is not always focused on things and events; it can also involve social responses and relationships. The fear is often associated with the presence of strangers or the departure of significant others known respectively as stranger wariness and separation anxiety, which appear sometime between 6 and 15 months. And there is even some indication that infants may experience jealousy as young as 6 months of age (Hart & Carrington, 2002).

Stranger wariness actually indicates that brain development and increased cognitive abilities have taken place. As an infant’s memory develops, they are able to separate the people that they know from the people that they do not. The same cognitive advances allow infants to respond positively to familiar people and recognize those that are not familiar. Separation anxiety also indicates cognitive advances and is universal across cultures. Due to the infant’s increased cognitive skills, they are able to ask reasonable questions like “Where is my caregiver going?” “Why are they leaving?” or “Will they come back?” Separation anxiety usually begins around 7-8 months and peaks around 14 months, and then decreases. Both stranger wariness and separation anxiety represent important social progress because they not only reflect cognitive advances but also growing social and emotional bonds between infants and their caregivers.

As we will learn through the rest of this module, caregiving does matter in terms of infant emotional development and emotional regulation. Emotional regulation can be defined by two components: emotions as regulating and emotions as regulated. The first, “emotions as regulating,” refers to changes that are elicited by activated emotions (e.g., a child’s sadness eliciting a change in parent response). The second component is labeled “emotions as regulated,” which refers to the process through which the activated emotion is itself changed by deliberate actions taken by the self (e.g., self-soothing, distraction) or others (e.g., comfort).

Throughout infancy, children rely heavily on their caregivers for emotional regulation; this reliance is labeled co-regulation, as parents and children both modify their reactions to the other based on the cues from the other. Caregivers use strategies such as distraction and sensory input (e.g., rocking, stroking) to regulate infants’ emotions. Despite their reliance on caregivers to change the intensity, duration, and frequency of emotions, infants are capable of engaging in self-regulation strategies as young as 4 months old. At this age, infants intentionally avert their gaze from overstimulating stimuli. By 12 months, infants use their mobility in walking and crawling to intentionally approach or withdraw from stimuli.

Throughout toddlerhood, caregivers remain important for the emotional development and socialization of their children, through behaviors such as labeling their child’s emotions, prompting thought about emotion (e.g., “why is the turtle sad?”), continuing to provide alternative activities/distractions, suggesting coping strategies, and modeling coping strategies. Caregivers who use such strategies and respond sensitively to children’s emotions tend to have children who are more effective at emotion regulation, are less fearful and fussy, more likely to express positive emotions, easier to soothe, more engaged in environmental exploration, and have enhanced social skills in the toddler and preschool years.


During the second year of life, children begin to recognize themselves as they gain a sense of the self as an object. The realization that one’s body, mind, and activities are distinct from those of other people is known as self-awareness (Kopp, 2011).[2] The most common technique used in research for testing self-awareness in infants is a mirror test known as the “Rouge Test.” The rouge test works by applying a dot of rouge (colored makeup) on an infant’s face and then placing them in front of the mirror. If the infant investigates the dot on their nose by touching it, they are thought to realize their own existence and have achieved self-awareness. A number of research studies have used this technique and shown self-awareness to develop between 15 and 24 months of age. Some researchers also take language such as “I, me, my, etc.” as an indicator of self-awareness.

Cognitive psychologist Philippe Rochat (2003) described a more in-depth developmental path in acquiring self-awareness through various stages. He described self-awareness as occurring in five stages beginning from birth.

Table 1. Stages of acquiring self-awareness
Stage Description
Stage 1 – Differentiation (from birth) Right from birth infants are able to differentiate the self from the non-self. A study using the infant rooting reflex found that infants rooted significantly less from self-stimulation, contrary to when the stimulation came from the experimenter.
Stage 2 – Situation (by 2 months) In addition to differentiation, infants at this stage can also situate themselves in relation to a model. In one experiment infants were able to imitate tongue orientation from an adult model. Additionally, another sign of differentiation is when infants bring themselves into contact with objects by reaching for them.
Stage 3 – Identification (by 2 years) At this stage, the more common definition of “self-awareness” comes into play, where infants can identify themselves in a mirror through the “rouge test” as well as begin to use language to refer to themselves.
Stage 4 – Permanence This stage occurs after infancy when children are aware that their sense of self continues to exist across both time and space.
Stage 5 – Self-consciousness or meta-self-awareness This also occurs after infancy. This is the final stage when children can see themselves in 3rd person, or how they are perceived by others.

Once a child has achieved self-awareness, the child is moving toward understanding social emotions such as guilt, shame or embarrassment, and pride, as well as sympathy and empathy. These will require an understanding of the mental state of others which is acquired around age 3 to 5 and will be explored in the next module (Berk, 2007).

Watch It

This video shows one study that demonstrates how toddlers become aware of their bodies around 18 months.

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Psychosocial development occurs as children form relationships, interact with others, and understand and manage their feelings. In social and emotional development, forming healthy attachments is very important and is the major social milestone of infancy. Attachment is a long-standing connection or bond with others. Developmental psychologists are interested in how infants reach this milestone. They ask such questions as: How do parent and infant attachment bonds form? How does neglect affect these bonds? What accounts for children’s attachment differences?

Researchers Harry Harlow, John Bowlby, and Mary Ainsworth conducted studies designed to answer these questions. In the 1950s, Harlow conducted a series of experiments on monkeys. He separated newborn monkeys from their mothers. Each monkey was presented with two surrogate mothers. One surrogate mother was made out of wire mesh, and she could dispense milk. The other surrogate mother was softer and made from cloth: This monkey did not dispense milk. Research shows that the monkeys preferred the soft, cuddly cloth monkey, even though she did not provide any nourishment. The baby monkeys spent their time clinging to the cloth monkey and only went to the wire monkey when they needed to be feed. Prior to this study, the medical and scientific communities generally thought that babies become attached to the people who provide their nourishment. However, Harlow (1958) concluded that there was more to the mother-child bond than nourishment. Feelings of comfort and security are the critical components of maternal-infant bonding, which leads to healthy psychosocial development.

Watch It

Harlow’s studies of monkeys were performed before modern ethics guidelines were in place, and today his experiments are widely considered to be unethical and even cruel. Watch this video to see actual footage of Harlow’s monkey studies.

Building on the work of Harlow and others, John Bowlby developed the concept of attachment theory. He defined attachment as the affectional bond or tie that an infant forms with the mother (Bowlby, 1969). He believed that an infant must form this bond with a primary caregiver in order to have normal social and emotional development. In addition, Bowlby proposed that this attachment bond is very powerful and continues throughout life. He used the concept of a secure base to define a healthy attachment between parent and child (1988). A secure base is a parental presence that gives children a sense of safety as they explore their surroundings. Bowlby said that two things are needed for a healthy attachment: The caregiver must be responsive to the child’s physical, social, and emotional needs; and the caregiver and child must engage in mutually enjoyable interactions (Bowlby, 1969).

A person is shown holding an infant.
Figure 1. Mutually enjoyable interactions promote the mother-infant bond. (credit: Peter Shanks)

While Bowlby thought attachment was an all-or-nothing process, Mary Ainsworth’s (1970) research showed otherwise. Ainsworth wanted to know if children differ in the ways they bond, and if so, how. To find the answers, she used the Strange Situation procedure to study attachment between mothers and their infants (1970). In the Strange Situation, the mother (or primary caregiver) and the infant (age 12-18 months) are placed in a room together.  There are toys in the room, and the caregiver and child spend some time alone in the room. After the child has had time to explore their surroundings, a stranger enters the room. The mother then leaves her baby with the stranger. After a few minutes, she returns to comfort her child.

Based on how the toddlers responded to the separation and reunion, Ainsworth identified three types of parent-child attachments: secure, avoidant, and resistant (Ainsworth & Bell, 1970). A fourth style, known as disorganized attachment, was later described (Main & Solomon, 1990).

The most common type of attachment—also considered the healthiest—is called secure attachment. In this type of attachment, the toddler prefers their parent over a stranger. The attachment figure is used as a secure base to explore the environment and is sought out in times of stress. Securely attached children were distressed when their caregivers left the room in the Strange Situation experiment, but when their caregivers returned, the securely attached children were happy to see them. Securely attached children have caregivers who are sensitive and responsive to their needs.

A photograph shows a person squatting down next to a small child who is standing up.
Figure 2. In secure attachment, the parent provides a secure base for the toddler, allowing him to securely explore his environment. (credit: Kerry Ceszyk)

With avoidant attachment, the child is unresponsive to the parent, does not use the parent as a secure base, and does not care if the parent leaves. The toddler reacts to the parent the same way they react to a stranger. When the parent does return, the child is slow to show a positive reaction. Ainsworth theorized that these children were most likely to have a caregiver who was insensitive and inattentive to their needs (Ainsworth, Blehar, Waters, & Wall, 1978).

In cases of resistant attachment, children tend to show clingy behavior, but then they reject the attachment figure’s attempts to interact with them (Ainsworth & Bell, 1970). These children do not explore the toys in the room, appearing too fearful. During separation in the Strange Situation, they become extremely disturbed and angry with the parent. When the parent returns, the children are difficult to comfort. Resistant attachment is thought to be the result of the caregivers’ inconsistent level of response to their child.

Finally, children with disorganized attachment behaved oddly in the Strange Situation. They freeze, run around the room in an erratic manner, or try to run away when the caregiver returns (Main & Solomon, 1990). This type of attachment is seen most often in kids who have been abused or severely neglected. Research has shown that abuse disrupts a child’s ability to regulate their emotions.

While Ainsworth’s research has found support in subsequent studies, it has also met criticism. Some researchers have pointed out that a child’s temperament (which we discuss next) may have a strong influence on attachment (Gervai, 2009; Harris, 2009), and others have noted that attachment varies from culture to culture, a factor that was not accounted for in Ainsworth’s research (Rothbaum, Weisz, Pott, Miyake, & Morelli, 2000; van Ijzendoorn & Sagi-Schwartz, 2008).

Watch It

Watch this video to better understand Mary Ainsworth’s research and to see examples of how she conducted the experiment.

Attachment styles vary in the amount of security and closeness felt in the relationship and they can change with new experiences. The type of attachment fostered in parenting styles varies by culture as well. For example, German parents value independence and Japanese mothers are typically by their children’s sides. As a result, the rate of insecure-avoidant attachments is higher in Germany and insecure-resistant attachments are higher in Japan. These differences reflect cultural variation rather than true insecurity, however (van Ijzendoorn and Sagi, 1999).  Keep in mind that methods for measuring attachment styles have been based on a model that reflects middle-class, US values and interpretation. Newer methods for assessing attachment styles involve using a Q-sort technique in which a large number of behaviors are recorded on cards and the observer sorts the cards in a way that reflects the type of behavior that occurs within the situation.

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Attachment is classified into four types: A, B, C, and D. Ainsworth’s original schema differentiated only three types of attachment (types A, B, and C), but, as mentioned above, later researchers discovered a fourth category (type D). As we explore styles of attachment below, consider how these may also be evidenced in adult relationships. We’ll come back to this idea in later modules.

Types of Attachments


A secure attachment (type B) is one in which the child feels confident that their needs will be met in a timely and consistent way. The caregiver is the base for exploration, providing assurance and enabling discovery. In North America, this interaction may include an emotional connection in addition to adequate care. However, even in cultures where mothers do not talk, cuddle, and play with their infants, secure attachments can develop (LeVine et. al., 1994). Secure attachments can form provided the child has consistent contact and care from one or more caregivers. Consistency of contacts may be jeopardized if the infant is cared for in a daycare with a high turn-over of caregivers or if institutionalized and given little more than basic physical care. And while infants who, perhaps because of being in orphanages with inadequate care, have not had the opportunity to attach in infancy can form initial secure attachments several years later, they may have more emotional problems of depression or anger, or be overly friendly as they make adjustments (O’Connor et. al., 2003).

Insecure Resistant/Ambivalent

Insecure-resistant/ambivalent (type C) attachment style is marked by insecurity and resistance to engaging in activities or play away from the caregiver. It is as if the child fears that the caregiver will abandon them and clings accordingly. (Keep in mind that clingy behavior can also just be part of a child’s natural disposition or temperament and does not necessarily reflect some kind of parental neglect.) The child may cry if separated from the caregiver and also cry upon their return. They seek constant reassurance that never seems to satisfy their doubt. This type of insecure attachment might be a result of not having their needs met in a consistent or timely way. Consequently, the infant is never sure that the world is a trustworthy place or that he or she can rely on others without some anxiety. A caregiver who is unavailable, perhaps because of marital tension, substance abuse, or preoccupation with work, may send a message to the infant they cannot rely on having their needs met. A caregiver who attends to a child’s frustration can help teach them to be calm and to relax. But an infant who receives only sporadic attention when experiencing discomfort may not learn how to calm down.


Insecure-avoidant (type A) is an attachment style marked by insecurity. This style is also characterized by a tendency to avoid contact with the caregiver and with others. This child may have learned that needs typically go unmet and learns that the caregiver does not provide care and cannot be relied upon for comfort, even sporadically. An insecure-avoidant child learns to be more independent and disengaged. Such a child might sit passively in a room filled with toys until it is time to go.


Disorganized attachment (type D) represents the most insecure style of attachment and occurs when the child is given mixed, confused, and inappropriate responses from the caregiver. For example, a mother who suffers from schizophrenia may laugh when a child is hurting or cry when a child exhibits joy. The child does not learn how to interpret emotions or to connect with the unpredictable caregiver.

How common are the attachment styles among children in the United States? It is estimated that about 65 percent of children in the United States are securely attached. Twenty percent exhibit avoidant styles and 10 to 15 percent are resistant. Another 5 to 10 percent may be characterized as disorganized.

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Psychosocial Development


smiling baby in a swing
Figure 3. Babies are born with different temperaments. Some are slow-to-warm-up while others are easy-going.

Perhaps you have spent time with a number of infants. How were they alike? How did they differ? Or compare yourself with your siblings or other children you have known well. You may have noticed that some seemed to be in a better mood than others and that some were more sensitive to noise or more easily distracted than others. These differences may be attributed to temperament. Temperament is an inborn quality noticeable soon after birth. Temperament is not the same as personality but may lead to personality differences. Generally, personality traits are learned, whereas temperament is genetic. Of course, for every trait, nature and nurture interact.

According to Chess and Thomas (1996), children vary on nine dimensions of temperament. These include activity level, regularity (or predictability), sensitivity thresholds, mood, persistence or distractibility, among others. These categories include the following:[3].

  1. Activity level. Does the child display mostly active or inactive states?
  2. Rhythmicity or Regularity. Is the child predictable or unpredictable regarding sleeping, eating, and elimination patterns?
  3. Approach-Withdrawal. Does the child react or respond positively or negatively to a newly encountered situation?
  4. Adaptability. Does the child adjust to unfamiliar circumstances easily or with difficulty
  5. Responsiveness. Does it take a small or large amount of stimulation to elicit a response (e.g., laughter, fear, pain) from the child?
  6. Reaction Intensity. Does the child show low or high energy when reacting to stimuli?
  7. Mood Quality. Is the child normally happy and pleasant, or unhappy and unpleasant?
  8. Distractibility. Is the child’s attention easily diverted from a task by external stimuli?
  9. Persistence and Attention Span. Persistence – How long will the child continue at an activity despite difficulty or interruptions? Attention span – For how long a period of time can the child maintain interest in an activity?

The New York Longitudinal Study was a long term study of infants, on these dimensions, which began in the 1950s. Most children do not have their temperament clinically measured, but categories of temperament have been developed and are seen as useful in understanding and working with children. Based on this study, babies can be described according to one of several profiles: easy or flexible (40%), slow to warm up or cautious (15%), difficult or feisty (10%), and undifferentiated, or those who can’t easily be categorized (35%).

Easy babies (40% of infants) have a positive disposition. Their body functions operate regularly and they are adaptable. They are generally positive, showing curiosity about new situations and their emotions are moderate or low in intensity. Difficult babies (10% of infants) have more negative moods and are slow to adapt to new situations. When confronted with a new situation, they tend to withdraw. Slow-to-warm babies (15% of infants) are inactive, showing relatively calm reactions to their environment. Their moods are generally negative, and they withdraw from new situations, adapting slowly. The undifferentiated (35%) could not be consistently categorized. These children show a variety of combinations of characteristics. For example, an infant may have an overall positive mood but react negatively to new situations.

No single type of temperament is invariably good or bad, however, infants with difficult temperaments are more likely than other babies to develop emotional problems, especially if their mothers were depressed or anxious caregivers (Garthus-Niegel et al., 2017).[4] Children’s long-term adjustment actually depends on the goodness-of-fit of their particular temperament to the nature and demands of the environment in which they find themselves. Therefore, what appears to be more important than child temperament is how caregivers respond to it.

Think about how you might approach each type of child in order to improve your interactions with them. An easy or flexible child will not need much extra attention unless you want to find out whether they are having difficulties that have gone unmentioned. A slow to warm up child may need to be given advance warning if new people or situations are going to be introduced. A difficult or feisty child may need to be given extra time to burn off their energy. A caregiver’s ability to accurately read and work well with the child will enjoy this goodness-of-fit, meaning their styles match and communication and interaction can flow. The temperamentally active children can do well with parents who support their curiosity but could have problems in a more rigid family.

It is this goodness-of-fit between child temperament and parental demands and expectations that can cause struggles. Rather than believing that discipline alone will bring about improvements in children’s behavior, our knowledge of temperament may help a parent, teacher or other caregiver gain insight to work more effectively with a child. Viewing temperamental differences as varying styles that can be responded to accordingly, as opposed to ‘good’ or ‘bad’ behavior. For example, a persistent child may be difficult to distract from forbidden things such as electrical cords, but this persistence may serve her well in other areas such as problem-solving.  Positive traits can be enhanced and negative traits can be subdued. The child’s style of reaction, however, is unlikely to change. Temperament doesn’t change dramatically as we grow up, but we may learn how to work around and manage our temperamental qualities. Temperament may be one of the things about us that stays the same throughout development.

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Link to Learning

Read the article “Lasting Effects of a Goodness- or Poorness-of-fit” from Psychology Today (https://www.psychologytoday.com/us/blog/the-long-reach-childhood/201312/lasting-effects-goodness-or-poorness-fit) to learn more about goodness-of-fit and poorness-of-fit.

Erikson’s Stages for Infants and Toddlers

Trust vs. mistrust

Erikson maintained that the first year to year and a half of life involves the establishment of a sense of trust. Infants are dependent and must rely on others to meet their basic physical needs as well as their needs for stimulation and comfort. A caregiver who consistently meets these needs instills a sense of trust or the belief that the world is a safe and trustworthy place. The caregiver should not worry about overindulging a child’s need for comfort, contact, or stimulation. This view is in sharp contrast with the Freudian view that a parent who overindulges the infant by allowing them to suck too long or be picked up too frequently will be spoiled or become fixated at the oral stage of development.

messy toddler girl covered with fingerpaint.
Figure 4. Exploring the environment allows the toddler to develop a sense of autonomy and independence.

Consider the implications for establishing trust if a caregiver is unavailable or is upset and ill-prepared to care for a child, or if a child is born prematurely, is unwanted, or has physical problems that could make them less desirable to a parent. However, keep in mind that children can also exhibit strong resiliency to harsh circumstances. Resiliency can be attributed to certain personality factors, such as an easy-going temperament and receiving support from others. A positive and strong support group can help a parent and child build a strong foundation by offering assistance and positive attitudes toward the newborn and parent.

Autonomy vs. shame and doubt

As the child begins to walk and talk, an interest in independence or autonomy replaces their concern for trust. The toddler tests the limits of what can be touched, said, and explored. Erikson believed that toddlers should be allowed to explore their environment as freely as safety allows and, in doing so, will develop a sense of independence that will later grow to self-esteem, initiative, and overall confidence. If a caregiver is overly anxious about the toddler’s actions for fear that the child will get hurt or violate others’ expectations, the caregiver can give the child the message that they should be ashamed of their behavior and instill a sense of doubt in their abilities. Parenting advice based on these ideas would be to keep your toddler safe, but let them learn by doing. A sense of pride seems to rely on doing rather than being told how capable one is (Berger, 2005).

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Ainsworth’s strange situation: a sequence of staged episodes that illustrate the type of attachment between a child and (typically) their mother
attachment: the positive emotional bond that develops between a child and a particular individual
autonomy vs. shame and doubt: Erikson’s second crisis of psychosocial development, during which toddlers strive to gain a sense of self-rule over their actions and their bodies
disorganized attachment (type D): a type of attachment that is marked by an infant’s inconsistent reactions to the caregiver’s departure and return
emotional regulation: the ability to respond to the ongoing demands of experience with the range of emotions in a manner that is socially tolerable and sufficiently flexible to permit spontaneous reactions, as well as the ability to delay spontaneous reactions as needed
goodness-of-fit: the notion that development is dependent on the degree of match between children’s temperament and the nature and demands of the environment in which they are being raised
insecure-avoidant attachment (type A): a pattern of attachment in which an infant avoids connection with the caregiver, as when the infant seems not to care about the caregiver’s presence, departure, or even return
insecure-resistant/ambivalent attachment (type C): a pattern of attachment in which an infant’s anxiety and uncertainty are evident, as when the infant becomes very upset at separation from the caregiver and both resists and seeks contact on reunion
secure attachment (type B): a relationship in which an infant obtains both comfort and confidence from the presence of their caregiver
secure base: a parental presence that gives children a sense of safety as they explore their surroundings
self-awareness: a person’s realization that they are a distinct individual whose body, mind, and actions are separate from those of other people
separation anxiety: fear or distress caused by the departure of familiar significant others; most obvious between 9-14 months
social smile: a smile evoked by a human face, normally first evident in infants about 6 weeks after birth
stranger wariness: fear is often associated with the presence of strangers where an infant expresses concern or a look of fear while clinging to a familiar person
temperament: inborn differences between one person and another in emotions, activity, and self-regulation, typically measured by the person’s responses to the environment
trust vs. mistrust: Erikson’s first crisis of psychosocial development, during which infants learn basic trust if the world is a secure place where their needs (food, comfort, attention) are met


  1. Thiam, M.A., Flake, E.M. & Dickman, M.M. (2017). Infant and child mental health and perinatal illness. In Melinda A. Thiam (Ed.), Perinatal mental health and the military family: Identifying and treating mood and anxiety disorders. New York, NY: Routledge.
  2. Kopp, C.B. (2011). Development in the early years: Socialization, motor development; and consciousness. Annual Review of Psychology, 62, 165-187.
  3. Thomas, A., & Chess, S. (1977). Temperament and development. New York: Brunner/Mazel
  4. Garthus-Niegel, S., Ayers, S., Martini, J., von Soest, T. & Eberhard-Gran, M. (2017). The impact of postpartum post-traumatic stress disorder symptoms on child development: A population based, 2-year follow-up study. Psychological Medicine, 47(1), 161-170.


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