At what age do puppies first start to learn fear that could affect them for life?

Puppies begin to develop their capacity for fear during the critical socialization period, which generally occurs between 8 to 10 weeks of age. This is a crucial timeframe when they are exposed to various social experiences, environments, and stimuli. Experiences during this age can significantly shape their emotional responses and behavior later in life. If they encounter negative or frightening experiences during this period, it can lead to lifelong fears or anxieties.

As they continue to grow, particularly before they reach approximately 16 weeks of age, the foundation for their social behavior is being established, making it essential to provide positive exposures to a variety of experiences during this time. Therefore, 8 to 10 weeks is considered the age when fear responses can first solidify, influencing their behavior well into adulthood.