1) Online interaction is more complex than it initially seems due to a lack of embodiment, embeddedness in contexts, and established interaction norms. Important perceptual cues are missing online like body language and side conversations.
2) Human interaction is typically an "artfully accomplished" team sport learned from birth, but online we lack a shared culture and rules of thumb to navigate unfamiliar virtual interactions.
3) People rely heavily on intuitive "System 1" thinking for in-person interactions, but must expend more effortful "System 2" thinking online where familiar heuristics do not always apply. This can make online interactions feel exhausting.