Overview:
According to recent theories of emotional development, most emotions have appeared by the age of 3 years. Emotional development refers to the process through which individuals acquire and understand emotions, express them, and regulate them effectively. It is an important aspect of human development and plays a significant role in social interactions, cognitive functioning, and overall well-being.

Key Points:
1. Emotional Development in Infancy:
- Infants are born with basic emotions such as joy, sadness, anger, and fear.
- They express these emotions through facial expressions, vocalizations, and body language.
- By 6 months of age, infants start to display a wider range of emotions, including surprise, disgust, and interest.
- They also begin to differentiate between positive and negative emotions in others.

2. Emotional Development in Toddlerhood:
- During toddlerhood (1-3 years), emotional development becomes more complex.
- Toddlers develop a sense of self-awareness and start to understand that others have different emotions.
- They learn to label their emotions and use simple words to express how they feel.
- Tantrums and emotional outbursts are common as toddlers struggle with emotional regulation.

3. Development of Complex Emotions:
- By the age of 3, children start experiencing and expressing more complex emotions such as pride, shame, guilt, and empathy.
- They begin to understand and respond to social cues, show concern for others, and display rudimentary forms of empathy.
- Children also become more aware of the social rules and expectations surrounding emotions.

4. Cultural Influences on Emotional Development:
- Cultural factors play a significant role in shaping emotional development.
- Different cultures have varying norms, values, and expectations regarding emotions.
- Children learn to express and regulate emotions based on the cultural context they are raised in.

5. Individual Differences:
- It is important to note that the timeline for emotional development can vary among individuals.
- Some children may develop emotions earlier or later than the average timeline.
- Factors such as genetic predispositions, temperament, and environmental influences can impact the pace of emotional development.

Conclusion:
In conclusion, recent theories of emotional development suggest that most emotions have appeared by the age of 3 years. However, it is important to consider individual differences and cultural influences when examining emotional development in children. Emotional development continues throughout life, and understanding and regulating emotions effectively is crucial for healthy social and emotional functioning.