But when it comes to establishing health risks, correlation plus animal studies is often the best we have to go on.

但是当涉及到确定健康风险时，相关性加上动物研究往往是我们最好的依据。

As such, they risk confusing correlation with causation: perhaps those who spend more time on social media are more prone to negative emotions in the first place.

这样的话，他们可能把原因与相关因素给混淆了。或许花费大量时间在社交媒体上面的人们本来就是比较悲观的人。