首因效應與近因效應是由美國心理學家洛欽斯（A.S.Lochins）提出。
首因效應指的是，雙方對此的「第一印象」將影響後續往來，即是「先入為主」帶來的效果。
首因效應是指在人際交往或印象形成過程中，第一次接觸到的信息對後續的印象產生更大的影響力。這是因為人們在形成印象時，往往會將首次接觸到的信息視為核心知識或記憶圖式，後續的信息則被整合到這個記憶圖式中。
案例案例
心理學家洛欽斯在一個實驗中向不同組的大學生介紹同一個陌生人，並在介紹時使用不同的順序。結果顯示，先提供的信息在描述陌生人時占優勢，即先入為主的效應。
應用:
在管理問題中，了解首因效應可以幫助管理者在初次接觸或介紹新成員時，選擇適當的信息順序，以營造正面的第一印象，從而建立良好的關係和合作。
The Primacy Effect and the Recency Effect were proposed by the American psychologist A.S. Lochins.
The Primacy Effect refers to the fact that the "first impression" of both parties will affect their subsequent interactions, i.e., the effect of "preconceptions."
The Primacy Effect means that in the process of interpersonal interaction or impression formation, the information first encountered has a greater influence on the subsequent impression. This is because when people form impressions, they often see the first encountered information as core knowledge or memory schema, and then integrate subsequent information into this memory schema.
Case Example:
In an experiment, psychologist Lochins introduced the same stranger to different groups of university students, using different orders of information. The results showed that the information provided first had an advantage in describing the stranger, i.e., the Primacy Effect.
Application:
In management problems, understanding the Primacy Effect can help managers choose appropriate information sequences when first encountering or introducing new members, in order to create a positive first impression and establish a good relationship and cooperation.