Although facial expressions of emotion seem to be innate and, to a certain degree, universal among human cultures, we are still able to exert control over our facial expressions. This finding suggests that the expression of emotion:

Affected by culture and environmental factors

Explanation:

Although facial expressions of emotion seem to be innate and, to a certain degree, universal among human cultures, we are still able to exert control over our facial expressions. This finding suggests that the expression of emotion can be affected by culture and environmental factors and sometime it is affceted by psychological experiences.