Final answer:
It is true that not all cultures conceive of gender and sexuality in a binary way. Examples include third gender categories like 'fa'afafine' in Samoa and 'kathoey' in Thailand, contradicting the rigid dichotomous gender concept prevalent in many Western societies.
Step-by-step explanation:
The statement that not all cultures fix sexuality and gender in a dichotomy is true. Cultures around the world exhibit a vast array of gender expressions and acknowledge more than just a binary system. For instance, certain Native American tribes recognize what was once referred to as 'berdache', individuals who adopt roles and traits of genders different from their biological sex. The Samoan 'fa'afafine' represents a third gender, recognized for embracing both masculine and feminine traits. Moreover, in Thailand, apart from male and female, the gender category of 'kathoey' exists, encompassing individuals we might classify as intersex or transgender in Western societies.
These cultural examples demonstrate that the binary understanding of gender is not a universal concept but rather a social construct deeply rooted in some societies, such as European and Euro-American, which tend to be more cisnormative. The anthropological studies and the global LGBTQIA+ movement have challenged these binary views and contributed to a more nuanced understanding of gender flexibility and the complexity of human sexuality.