For many companion kittens, the early socialization window (between about two and nine weeks of age) occurs while they’re in foster care, and these formative experiences can significantly influence their behavioral development. Prolonged negative emotions like fear not only harm their well-being, but also increase their vulnerability to physical illnesses and serious behavioral problems such as aggression. This makes it vital to identify and address these emotional issues early on.

Thus, this study set out to examine foster parents’ kitten management practices and identify factors that may predict fear behaviors reported by foster parents in kittens approaching adoption age.

Researchers conducted an online survey of people fostering kittens worldwide. Recruitment was done through social media, the authors’ research website, and animal welfare organizations. Foster parents had to be 18 years of age or older and currently have kittens between seven and nine weeks of age who had lived with them for at least one week. They provided data on:

• Household demographics, fostering experience, and personality traits;
• Litter-level information including maternal presence and stimulus exposures;
• Individual kitten characteristics like sex and coat color; and
• Individual kitten behavioral responses to unfamiliar people and objects.

To help with the behavior assessments, foster parents were given an infographic that outlined typical kitten fear responses such as avoidance, freezing, crouching, ears back, fur standing on end, and aggression.

Stimulus exposure was assessed via two methods:

1. Exposure to non-social enrichment items, such as toys, puzzle feeders, hiding areas, and scratching materials; and
2. Exposure to social and non-social experiences like handling, climbing stairs, and encountering different surfaces.

These exposures were included because they encourage exploration and play, helping kittens engage with their environment and develop natural feline behaviors. Exposures were measured in terms of both variety and amount.

In total, 72 foster parent responses (from an initial 89) met completion and inclusion criteria. Participants were predominantly women (93%) from mid-sized Canadian communities with substantial fostering experience (over four years on average). They scored lower in extraversion but higher in agreeableness, conscientiousness, emotional stability, and openness compared to population norms.

The survey responses represented a total of 235 kittens. The kittens were evenly divided between males (49%) and females (51%). Litter sizes ranged from one to eight, with an average of about four kittens per litter. Kittens averaged four weeks of age at intake, and about a third (33%) were reported as fearful when they entered foster care.

Foster parents interacted with kittens for about three hours daily on average, providing various enrichments such as balls, feather wands, scratching posts, covered beds, perches, boxes, tunnels, and paper bags. General handling was the most common social exposure, while movement opportunities such as climbing stairs were the most frequent non-social exposure. Transportation and exposure to unfamiliar animals were least provided.

Multiple factors significantly influenced whether kittens displayed fear toward unfamiliar people. Kittens who were already fearful when they first entered foster care were more likely to remain fearful of strangers at adoption age. Interestingly, kittens who received cognitive enrichment opportunities, like puzzle feeders and training, were more likely to show fear toward unfamiliar people as well, which the researchers hadn’t expected. The foster parent’s personality also mattered: kittens cared for by emotionally stable foster parents showed more fear toward strangers. On the positive side, kittens who received plenty of exposure to social stimuli were less afraid of unfamiliar people.

As with fear of unfamiliar people, kittens who were fearful at intake were more likely to remain fearful of unfamiliar objects at adoption age. None of the other factors, including the amount of exposure to social or non-social stimuli, significantly influenced object-related fear. Results also revealed that the specific foster home environment and litter characteristics had a much stronger influence on fear of objects than on fear of people, suggesting that a kitten’s early environment plays a crucial role in shaping how they respond to new objects.

In summary, this study reveals that socialization benefits depend on kittens’ initial fear levels. While social exposure reduced fear toward strangers, it didn’t affect object-related fear. Counterintuitively, cognitive enrichment opportunities increased stranger-related fear, suggesting they may overwhelm kittens developmentally. With around a third of kittens entering foster care already fearful — and likely to remain so — better socialization strategies for fearful kittens are needed. The findings also highlight the need to understand socialization quality and accurately identify fear states to customize socialization appropriately.

There are several significant limitations to this study, including reliance on subjective foster parent assessments, a cross-sectional design limited to kittens between seven to nine weeks of age, and a demographically skewed sample toward predominantly female, Canadian, experienced fosters. The absence of a control group, retrospective reporting biases, and focus on specific behavioral contexts also restrict broader conclusions.

Despite these limitations, the research findings yield important insights that translate into practical recommendations for advocates to enhance kitten foster care practices:

• Personalize the socialization approach: Tailor socialization based on a kitten’s initial fear level. Kittens fearful at intake often remain fearful and need specialized, gentle approaches rather than one-size-fits-all methods.
• Balance enrichment carefully: While positive social interactions reduce fear toward strangers, complex cognitive enrichments may overwhelm some kittens. Introduce new items and experiences gradually and closely monitor responses.
• Create safety and recognize fear: Provide hiding places for kittens to self-regulate, and learn to identify subtle fear signals such as flattened ears, freezing, and crouching to adjust approaches accordingly.
• Institutional support is needed: Shelters should develop specialized training for fostering fearful kittens and use knowledge of fear responses to match kittens with appropriate adopters who understand their needs.