The native of Seattle, Washington, wrote about her eye-opening first brush with whitening products, umbrellas to protect people from the sun – rather than the rain – as well as women swimming at the beach in jeans and long-sleeved shirts. She also talked about meeting women who chose to do their street shopping in the evening or late afternoon, once the sun began to set.

Instead of hiding from the sun, most Caucasians bask under its brightness to get a darker skin color.

In Gamlam's country alone, this ideal of beauty has fueled the growth of a $5 billion indoor-tanning industry despite the associated risks of skin cancer, reports say. Gamlam likes to sunbathe by the beach or pool, though she says she's careful about overexposure that could lead to skin disease.

How did people develop such divergent ideas of beauty that lead some to endanger their lives in its pursuit?

Turns out, the answer is emulation of the lifestyles of their respective societies' rich and cultured.

In the West at the beginning of the 20th century, only the nobility and wealthy could afford to vacation at new resorts in places like southern France, Italy and Spain, says Bernd Schmitt, a professor of international business marketing at Columbia Business School.

They'd return from these beach trips with tans. So, darker skin became associated with the good life in the West, he explains.

In China, fair skin has been associated since ancient times with positive notions like "elegance, higher status and worldly city life rather than country life", Schmitt says in a phone interview from Singapore, where he serves as executive director of the Institute for Asian Consumer Insight and as a visiting professor at Nanyang Technological University.

"When you work in the countryside, you get, of course, darker skin because you expose yourself to the sun and to the elements."

The common use of white-skinned models in the ads for Western fashion brands may add to the appeal of fairer skin in China, he says.

Gamlam has graduated from college and is back in Beijing, waiting to start a teaching job at a middle school in Ningbo, Zhejiang province. Among the things the 22-year-old carried back from the US is a white umbrella with a lacy pattern of pink roses and golden swirls – a souvenir from her China trip last year.

"I thought I should bring it back with me because I would only ever use it here," she says.

Xu Junqian in Shanghai contributed to this report.