Men were tentative when writing about make-up or other stereotypically feminine topics, especially when they thought they were writing to a woman, he found. For example, one man, believing he was corresponding with a woman, wrote: "… maybe girls prefer the quality of products at Sephora over other major department stores? I don't know."

Women were tentative when writing about changing flat tires and other stereotypically masculine topics, especially when they thought they were writing to a man. For example, one woman, believing she was giving instructions to a man, wrote: "I think they start out by raising the whole car, or maybe just the one tire with a tire jack?"

To change a flat, start with putting the emergency brake on loosening the lug nuts, then jacking up the car.