There is an order of severity as to what one might consider being rude:
In the field of linguistics research, an emphasis on the investigation and teaching of politeness has overshadowed the study of its counterpart, rudeness. Certain early seminal works in the field of linguistic pragmatics that dealt with the issue of politeness and rudeness have emphasized 'positive' aspects of conversation as being the universal norms of conversation, and saw rudeness as a defective mode of communication. More recent research has asserted that most rudeness serves functional or instrumental purposes in communication, and considers rudeness to be an important part of a person's pragmatic competence. Research in the field of pragmatic competence never really addressed common spoken rudeness and its functional aspects until the mid-1990s.
Prior to that time, most research focused on politeness and precluded the instrumental or 'useful' nature of rudeness in speech (Brown & Levinson, 1987; Grice, 1975; Lakoff, 1973). Whether it was an aberration of the "two rules" of pragmatic competence according to Lakoff (1973): (1) Be clear,(2) Be polite; or whether it violated the assumed universal norms of conversation of truthfulness, politeness and relevancy (Grice, 1975), rudeness was seen as pragmatic failure at being polite. Likewise, the politeness framework proposed in Brown and Levinson's (1987) work is also based on the idea that politeness is the norm even when employing most of the five basic strategies they identified for performing 'face-threatening acts' (FTAs; e.g., requests, complaints, refusals, etc.), acts that intrinsically threaten a speaker’s public self-image (face) or that of another (Brown & Levinson, 1987, pp. 60-61). Brown and Levinson (1987) propose that talk participants choose from a hierarchy of five basic strategies for performing an FTA. Ordered from the lowest to the highest risk of face loss, they are: 1) bald, on-record; 2) positive politeness; 3) negative politeness; 4) off record; and 5) don’t do the FTA (Brown & Levinson, 1987, p. 60). Talk participants are generally expected to use these politeness strategies, or 'redressive actions' (linguistic additions, modifications), in order to avoid face loss when performing an FTA. Additionally, certain variables lend a particular 'weight' to the FTA, such as power relationships between the speaker and hearer, social distance, and the rank of the imposition (Brown & Levinson, 1987, pp. 15, 74, 76-78).
These variables supposedly determine which strategy the speaker will use when performing the FTA; meaning that with the increasing weight of the FTA (and the resulting increased risk of face loss), the more likely that the speaker will use a strategy that is higher in the hierarchy of the politeness strategies. Brown and Levinson's first strategy in the hierarchy (perform the FTA without redressive action, baldly) is likely performed when the estimation of risk of face-loss is low, and the use of such a strategy could possibly allow for the existence of rudeness. Indeed, the authors mention that, in addition to the use of politeness strategies, the content of the speech needs to be evaluated when considering the 'politeness' of an FTA:
"The semantics and pragmatics of utterances must be taken into account in assessing degree of face redress; if the overt content of an utterance is rude, for example, politeness strategies won’t necessarily redeem it." (Brown & Levinson, 1987, p. 22)
However, Brown and Levinson leave this mouthful about 'rude content' without further definition or analysis. One of the first real investigations into spoken rudeness was conducted by Robin Lakoff (1989) in her research on rudeness used in professional settings (therapists' offices, courtrooms), a variety of rudeness that she named 'strategic rudeness.' Lakoff asserts that strategic rudeness is used by prosecutors and therapists to force their interlocutors (a courtroom defendant or patient) to talk or react in a certain way. Although her research delved into the uses of rudeness to fulfill a purpose, it only addressed rudeness that is used in situations where the norms of conversational interaction are radically different from those of everyday life.
Gabriele Kasper (1990) gives us the earliest definition of rudeness in an academic paper. In her discussion of Lakoff's (1989) research on strategic rudeness, Kasper (1990) defines rudeness as speech that is "constituted by deviation from whatever counts as politic in a given social context, is inherently confrontational and disruptive to social equilibrium" (Kasper, 1990, p. 208). This definition is important, in that it marks rudeness as speech which is confrontational at its core. Although Kasper (1990) further defines rudeness as 'motivated' and 'unmotivated,' her definitions do not make use of natural data.
It is not until Leslie Beebe's research comes along in the early to mid-1990s that data on naturally occurring instances of rudeness in everyday conversation is collected. Drawing from Lakoff's (1989) idea of strategic rudeness, Beebe (1993a, 1993b, 1994, 1995) similarly proposes the concept of instrumental rudeness; rudeness that is meant to achieve a goal. Like Lakoff (1989) and Kasper (1990), Beebe (1995) believes that rudeness is confrontational behaviour, and indeed in her research, she found that "hostility seemed to pervade the data" (Beebe, 1995, p. 156). In her study of naturally occurring rudeness in New York City, Beebe (1995) provides her own definition of rudeness:
"In this study, rudeness is defined as a face threatening act (FTA)- or feature of an FTA such as intonation- which violates a socially sanctioned norm of interaction for the social context in which it occurs. It is only rudeness if it receives insufficient redressive action to mitigate its force or, of course, if it does not occur in a context, such as intimacy or emergency, that would negate the need for redressive action. Consequently, it causes antagonism, discomfort, or conflict and results in some disruption to the social harmony. The idea that socially sanctioned norms of interaction are violated is central to the perception of rudeness." (Beebe, 1995, p. 159)
In this definition, Beebe (1995) asserts that rudeness is an FTA, or a feature of an FTA, that has not been mitigated by redressive action and does not occur between intimates or in emergency situations. Essentially, rudeness is a bald, on-record face attack, and not a failed attempt at politeness. This definition would also most likely preclude culturally-specific ritual insults, verbal games, or manners of speech that are used among members of certain social groups. Labov (1972) argues that ritual insults, or 'sounding,' follow certain linguistic, organizational, and interactional rules. If such speech among members of a cultural in-group could be seen as following 'socially sanctioned norms of interaction' (as Labov, 1972, argues) where there is a low risk of face-loss, it would most likely not be considered 'rude speech,' according to Beebe's (1995) definition of rudeness. Beebe (1995) also excludes from her definition: perceived rudeness originating from the differing conversational styles between "high considerate-ness" and "high involvement" speakers, as explained by Tannen (1984, 1990).
Most importantly to this study, the natural data in Beebe's (1995) paper supports her contention that most rudeness in everyday speech "is frequently instrumental, and is not merely pragmatic failure" (Beebe, 1995, p. 154). She gives the following example, and her interpretation of it:
Bicyclist: "Hey! Hey! Hey! You fuck!" It is difficult to imagine how he might have had politeness as his goal. It seems far-fetched to analyze this encounter as perception of rudeness due to clashing conversational styles. It also appears unlikely that this is cross cultural pragmatic failure. More probably, the bicyclist wanted to be instrumentally rude." (Beebe, 1995, pp. 154-155; italicized data slightly edited)
The bicyclist's utterance is a bald, on-record FTA that is meant to offend the taxi driver. Beebe (1995) uses this and other examples to show that talk participants will intentionally use rudeness to fulfill instrumental needs in their lives. She explains that the vast majority of the rudeness in the data she compiled was "…perhaps not intentional in the sense that it was consciously planned in advance, but that was intentional in the sense that it fulfilled a function that the speaker intended, and it was not failed politeness." (Beebe, 1995, p. 166)
Beebe (1995) also asserts that the examples in her study prove that most rude speakers are attempting to accomplish one of two important instrumental functions: 1) to vent negative feelings, and/or 2) to get power (in the above case of the bicyclist, to vent frustration at the taxi driver and/or perhaps to get the taxi driver to hurry up and turn out of the way) (Beebe, 1995, p. 159). Arent (1998) points out that although under Brown and Levinson's politeness framework such bald, on-record FTAs are employed only when the estimated risk of face loss is low, Beebe's (1995) data shows that "in some circumstances, talk participants will deliberately employ FTAs without regard to the risk of face loss to the hearer" (Arent, 1998, p. 48). Considering its deliberate nature and pervasiveness in the real world, Beebe (1995) believes that instrumental rudeness should be viewed as a part of pragmatic competence, even though both the fields of pragmatics and ESL teaching still regard politeness as the norm and regard rudeness as an aberration of politeness (Beebe, 1995, p. 156). She asserts that instrumental rudeness is a competency of a native English speaker, and that like native speakers, ESL students "have to learn to get power/control and express negative feelings — but in appropriate ways (Beebe, 1995, p. 167).