Relevant excerpt
Harassment is the creation of a hostile or intimidating environment in which inappropriate conduct, because of its severity and/or persistence, is likely to interfere significantly with an individual’s work or education, or affect adversely an individual’s living conditions.
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Harassment becomes unlawful where 1) enduring the offensive conduct becomes a condition of continued employment, or 2) the conduct is severe or pervasive enough to create a work environment that a reasonable person would consider intimidating, hostile, or abusive.
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Offensive conduct may include, but is not limited to, offensive jokes, slurs, epithets or name calling, physical assaults or threats, intimidation, ridicule or mockery, insults or put-downs, offensive objects or pictures, and interference with work performance.
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Some kinds of behavior that are clearly intended to harass, while inappropriate and not tolerated at Caltech, may not be unlawful. Behavior evidently intended to dishonor such characteristics as race, gender, gender expression or identity, national origin or ethnic group, religious belief, sexual orientation, age, or disability is contrary to the pursuit of inquiry and education and may be discriminatory harassment and violate the law. These types of behavior may be dealt with through the student disciplinary process or through supervisory intervention, including the Caltech progressive disciplinary process. …
A single incident, if unusually severe, may constitute sexual harassment. Some examples of such behaviors that may constitute harassment: … A student tells racially offensive jokes within a study group session with other students.