中文摘要：

一系列实验发现消费者多样化寻求行为随选择集增大而呈现倒U型变化,这是由于过大选择集情况下消费者倾向于采取启发式信息处理策略导致多样化寻求行为降低。同时,个体的认知需求水平调节选择集大小与多样化寻求行为间的倒U型关系。此外,通过操纵个体认知困难,理论机制进一步得到验证：在认知困难条件下,消费者也会因采用启发式信息处理策略而导致多样化寻求行为显著降低。

英文摘要：

Firms today offer more diverse products to induce consumption. Does the variety of choices always enhance consumers＇ choices of more varieties？ Intuitively, the larger the choice set size, the more varieties consumers will choose. However, the present research argued and found that there was an inverted-U relationship between choice set size and variety seeking. Specially, as choice set size increased, consumers＇ variety seeking first increased and then decreased. When choice set was too large, consumers were more likely to use heuristic processing of information, which led to the decrease of variety seeking. Studies 1A and 1B first showed the inverted-U relationship between choice set size and variety seeking with different products. Both experiments used a single factor between-subject design with three choice set size groups： a small choice set （6 flavors）, a moderate choice set （12 flavors）, and a large choice set （30 flavors） of yogurt （Study 1A） or ice cream （Study 1B）. Subjects were randomly assigned to one of the three choice set size groups. Results showed that, for both experiments, consumers＇ variety seeking first increased as choice set size increased from small to moderate, but consumers＇ variety seeking then decreased when choice set size increased from moderate to large, supporting the inverted-U relationship between choice set size and variety-seeking （H1）. Studies 2A and 2B aimed to test the proposed underlying mechanism, namely the heuristic information processing, by examining the moderation effect of individuals＇ need for cognition （NFC）. Study 2A used a 3 choice set size （6 vs. 12 vs. 30）× 2 NFC （low vs. high） between-subject design and showed that NFC moderated the inverted-U relationship. Specifically, the inverted-U relationship was only observed for low-NFC participants, but not for high-NFC participants （H2）. Furthermore, in the large choice set condition （30 flavors）, participants with low NFC showed more variety seeking than