Data from: Free-ranging dogs prefer petting over food in repeated interactions with unfamiliar humans

Dogs (Canis lupus familiaris) are the first species to have been domesticated, and unlike other domesticated species, they have developed a special bonding with their owners. The ability to respond to human gestures and language, and the hypersocial behaviours of dogs are considered key factors that have led them to become man's best friend. Free-ranging dogs provide an excellent model system for understanding the dog-human relationship in various social contexts. In India, free-ranging dogs occur in all possible human habitations. They scavenge among garbage, beg for food from humans, give birth in dens close to human habitations, and establish social bonds with people. However, there is ample dog-human conflict on the streets, leading to morbidity and mortality of dogs. Hence the ability to assess an unfamiliar human before establishing physical contact could be adaptive for dogs especially in the urban environment. We tested a total of 103 adult free-ranging dogs to investigate their response to immediate social and long-term food and social rewards. The dogs were provided a choice of obtaining a food reward either from the experimenter's hand or the ground. The dogs avoided making physical contact with the unfamiliar human. While immediate social reward was not effective in changing this response, the long-term test showed a strong effect of the social contact on the dogs' response. Our results revealed that these dogs tend to build trust based on affection, and not food rewards. The study provides significant insights into the dynamics of dog-human interactions on the streets and subsequent changes in behaviours of dogs through the process of learning.家犬（Canis lupus familiaris）是首个被驯化的物种，与其他驯化物种不同，它们与人类主人形成了特殊的情感联结。家犬对人类手势与语言的响应能力，以及其高度社会化的行为，被认为是使其成为人类挚友的关键因素。自由漫游犬（free-ranging dogs）为在各类社会情境中探究犬-人互动关系提供了极佳的模型体系。在印度，自由漫游犬遍布各类人类聚居区域，它们会在垃圾中觅食、向人类乞食，在靠近人类聚居地的洞穴中产仔，并与人类建立社会联结。然而街头存在大量犬类与人类的冲突，造成犬类的发病与死亡。因此，在建立肢体接触前先对陌生人类进行评估的能力，对犬类而言具有适应意义，在城市环境中尤为如此。本研究共测试了103只成年自由漫游犬，以探究它们对即时社交奖励、长期食物奖励与长期社交奖励的响应情况。实验为犬类提供了两种获取食物奖励的选择：从实验人员手中获取，或从地面获取。结果显示，犬类均避免与陌生实验人员发生肢体接触。尽管即时社交奖励无法有效改变这一行为倾向，但长期测试结果表明，社交接触对犬类的行为响应具有显著影响。本研究结果表明，此类犬类倾向于基于情感而非食物奖励建立信任。本研究为街头犬类与人类互动的动态过程，以及犬类通过学习过程产生的后续行为变化提供了重要的理论见解。