He writes:"when body language conflicts with the word that  are being said，

the body language will be the more 'truthful' in the sense of revealing true feeings."

当肢体语言和他正在说的话相互冲突时，肢体语言更加能表达他的真实想法。

老师，又遇到了the more adj，不明白为什么要加定冠词the?

谢谢老师。