Out of group attitudes are marked by: 

Group attitudes play a significant role in shaping social interactions, identity formation, and intergroup relationships.Key Points

• Out-group attitudes are marked by a sense of differences, as individuals perceive members of an out-group as distinct from their own group.
• These differences can be based on cultural, social, economic, or ideological factors, influencing perceptions and interactions.
• Out-group differentiation often leads to stereotypes, biases, and social distancing, affecting group dynamics.
• Research in social psychology suggests that people tend to view out-group members as less similar, less trustworthy, or even as competitors, which can sometimes contribute to discrimination or prejudice.

Hint

• Some degree of differences implies a milder distinction, but out-group attitudes are typically characterized by a clear sense of separation rather than minimal differences.
• Mutual interest is more associated with cooperation between groups, which does not define out-group attitudes.
• Conflicts can arise due to out-group distinctions, but they are an outcome rather than an inherent characteristic of out-group attitudes.

Hence, the correct answer is a sense of differences.