Bias.

Nepalese Porters May Be World's Most Efficient Haulers.

What is the article about?
The article is about what scientists say on how the porters do it: They use less energy than other people would require for the same work.

Are there biases in this article? If yes, is the bias against or for someone or something?
Yes, bias for.

Explain the bias and provide examples

It is bias towards napalese porters as they feel as though napalese porters are the most effective haulers.

His latest study, which appears tomorrow in the journal Science, now suggests that the porters of Nepal are even more efficient at their tasks.

It's amazing how universal carrying loads on the head is—except in Western Europe and North America,"

She added that the feat is particularly impressive because "they're [generally] not very well equipped [and] have very bad shoes.