In daily life, people make causal inferences to understand interactions around them. This thesis addresses how people make a particular type of causal inference based on the implicit causality (IC) of interpersonal verbs. Interpersonal verbs describe events between two protagonists and implicit causality refers to the bias that people may have to attribute the cause of the event to one of the two protagonists. For example, when reading the sentence John annoyed Peter, because…, most people tend to consider John, the first protagonist as the causer of the annoyance. In contrast, when reading a similar sentence like John criticized Peter, because…, most people tend to attribute the cause to Peter, the second protagonist. In the literature on implicit causality, the first protagonist is referred to as the NP1, the first noun phrase, and the second protagonist as the NP2, the second noun phrase. Furthermore, verbs like annoy with a bias to the NP1 are called IC1 verbs, and verbs like criticize with a bias to the NP2 are called IC2 verbs. It has been shown that IC bias is, for the most part, determined by the semantics of the verbs (e.g., Brown & Fish 1983). Yet, it has been discussed that non-semantic factors might also influence the IC bias (Pickering & Majid 2007). And the aim of the thesis is to study how the IC bias is influenced by socio-psychological and syntactic factors. Chapter 1 presents a theoretical background on how the IC bias has been studied in previous literature. As mentioned, the IC bias has been explained in terms of verb semantics. An agent role of agent-patient verbs (e.g., help) is considered as the causer of the action described by the verbs with an IC1 bias. In contrast, a stimulus role of stimulus-experiencer verbs (e.g., annoy) and experiencer-stimulus verbs (e.g., hate) is considered as the causer of the mental states described by the verbs, with an IC1 and IC2 biases, respectively. More recently, the trend has been moved to study how non-semantic factors influence the IC bias. In this thesis, we start from the observation that effects of implicit causality always ‘happen’ in context when verbs are used in sentences and scenarios. We consider socio-psychological and cultural variables could modify the event types evoked by the IC verbs. We investigate how self-perspective, group membership, a syntactic factor and culture might influence the IC bias. Chapter 2 addresses how self-perspective and culture might influence the IC bias. Most IC studies focus on how people choose the causer from a neutral perspective, that is, readers are onlookers of the events (see  Rudolph & Försterling 1997 for a review of IC studies). Different from these studies, we study once people are involved in the event, how they choose the causer, that is, how self-serving bias (SS bias) influences the IC bias. The SS bias is a tendency that people attribute positive events to themselves and that they avoid attributing negative events to themselves, in order to keep a good image of themselves. We hypothesize that this SS bias would influence the IC bias in a way that when people are involved in the IC verb sentences as one of the two protagonists, compared to the scenarios when they are not involved, they would be more likely to avoid choosing themselves as the causer of negative IC verb sentences and more likely to choose themselves as the causer of positive IC verb sentences. We also hypothesize that this tendency would be stronger among Dutch people than Chinese people. This is because this SS bias effect is claimed to be stronger in ‘self-enhancing’ Western cultures than in Eastern cultures (Mezulis et al. 2014). We present Dutch and Chinese participants with three versions of implicit causality sentences, a version in a neutral perspective (i.e., IC1 verb: Peter amazed John; IC2 verb: John criticized Peter), and two self perspectives, one in which the self takes up the biased position (biased-self, i.e., NP1 in IC1 verbs I amazed John; NP2 in IC2 verbs John criticized me), and one in which the self does not take up the biased position (non-biased-self, i.e., NP2 in IC1 verbs: Peter amazed me; NP1 in IC2 verbs: I criticized Peter). The sentences are either positive or negative. We ask the participants to choose a causer, to complete the sentences, and to carry out a causal judgment task. The results show that the participants judge sentences with the self-perspective in accordance with the self-serving bias. Culture, however, does not have an effect. The findings show that the IC bias is influenced by the self perspective, and that the effect of culture on the IC bias is not strong in linguistic measures. Chapter 3 further examines the influence of self-perspective and culture, and extends the research with group membership. Apart from the SS bias, group membership has been believed to influence how people interact with each other (Tajfel & Turner 1979). People tend to favor ingroup over outgroup, or to disfavor outgroup over ingroup, an intergroup bias (IG bias), in order to keep a good group relationship. This IG bias is claimed to be stronger among Eastern people than Western people, because Eastern cultures are collectivistic-oriented, while Western cultures are individualistic-oriented (Hofstede 1980; 2001). The aim of the chapter is to investigate to what extent the IG bias would modify the IC bias. We present Dutch and Chinese participants, as representatives of Western and Eastern cultures, respectively, with the two self perspectives of implicit causality sentences in scenarios. In the scenarios, the other protagonist is manipulated either as an ingroup or an outgroup member to the participants. We limit ourselves to only negative IC verb sentences, because the literature indicate that it is more likely to find an effect of group membership for negative events. We ask the participants to choose a causer and to complete the sentences. The results again confirm the effect of the self perspective in accordance with the SS bias. However, the results do not support the effect of culture or group membership. The findings suggest that when the SS bias is in conflict with the IG bias, the motivation to protect a good self-image might be stronger than that to maintain a good group relationship. Chapter 4 is concerned with how self perspective, culture, group, and polarity, might influence types of causes people make. Many IC studies have asked participants to complete IC verb sentences and have only focused on the choices that people made in IC verb sentences, as we do in Chapters 2 and 3. Very few studies, however, have focused on the type of causes the participants provide in the completions and how the completions relate to the IC verbs. We study how the socio-psychological factors in previous chapters influence the linguistic characteristics of completions of IC verb sentences, in particular stability and polarity. We focus on analyzing the relation between the polarity of IC verbs and the stability of the completions of the IC verb sentences both automatically and manually. Results show that in negative IC verb sentences, participants tend to produce fewer stable completions with them than others being causers, supporting an SS bias effect. In positive IC verb sentences, we did not find such a pattern. The relatively stronger effect in the negative IC verb sentences than in the positive IC verb sentences is in line with a general phenomenon that negativity triggers a stronger effect than positivity (Baumeister et al. 2001). Moreover, the tendency to produce fewer stable completions when people themselves are causers is weaker among Chinese participants than Dutch participants, supporting a weaker SS bias in Eastern cultures than Western cultures. Yet, we do not find evidence supporting the IG bias influencing the completions. Furthermore, we find that positive IC verbs trigger more stable completions than negative IC verbs. This is in line with findings from Beukenboom and Semin (2006) that positivity leads to more heuristic or global processing while negativity triggers a more detail-oriented processing style. Together, these findings suggest that some of the socio-psychological factors in previous chapters influence the IC bias in a subtle way in terms of the types of causes in completions. Chapter 5 investigates how sentence structures influence the IC bias. Two typical Chinese sentence structures are used: a direct object NP in a subject verb object (SVO) structure and an NP preceded by a co-verb in a subject co-verb object verb (SCOV) structure. Compared to the SVO structure, the object in the SCOV structure has been assumed to be either upgraded or downgraded (Cheng & Almor 2017a; Zhan et al. 2020). Chinese participants are asked to read Chinese IC verb sentences in these two sentence structures using a completion task and a choice task. The results do not show a strong effect of sentence structure on the IC bias. We only find a weak effect that the participants tend to choose the object in the SVO structure more often than in the SCOV structure in weak IC1 verb sentences. The findings suggest more support for the downgrading than the upgrading influence of the SCOV structure on the IC bias, compared to the SVO structure. We believe the weak modifying effect of the SCOV sentence structure might be because the object in the structure is oblique and less accessible than that in the SVO structure. Finally, Chapter 6 concludes the thesis with a discussion on the main findings in the thesis related to the existing IC theories. The thesis confirms the determining role of verb semantics in the IC bias. The thesis also shows a modifying effect of non-semantic factors on either the IC bias strength or the types of causes people provide for IC verb sentences. The thesis shows support of a modifying effect of self perspective on the IC bias strength, in accordance with the self-serving bias effect. However, the thesis does not show such support for the influence of group membership or culture on the IC bias strength. Yet, a further investigation on linguistic characteristics of the completions of the IC verb sentences suggests that some of the non-semantic factors, i.e., self perspective, culture, and polarity of IC verbs, influence the stability of causes that people provide for interpersonal events evoked by the IC verbs. Moreover, we find a weak effect that sentence structure might influence the IC bias strength in Chinese: people tend to choose the objects in the SCOV structure less often than in the SVO structure in weak IC1 verb sentences. In sum, this thesis shows that when people consider causes of interpersonal events, they are influenced by socio-psychological factors. In order to better understand the IC bias, it is worthwhile to study not only the IC bias strength as indicated by referential choices in the IC verb sentences, but also by the types of causes people provide for the IC verb sentences. Yet, it is undeniable that the semantics of verbs is the dominant factor that determines how people consider the causes. This means that language plays an important role in causal inferences in interpersonal interaction.