If you can understand well, and you answer it wrongly, then you must sit and analyse
why the correct answer appeared wrong to you?
Why the wrong answer is so tempting?
Once you find this you can improve, basically the we fall for the trap of the wording, For example if the passage speaks about 'Human intelligence' and the answer with the word 'Human thinking' will be tempting for us, we should not generalise, careful with those wordings. It is not easier , needs a lot of practice to hit the problem this way.
And always watch out for extreme answer choices, with words such as never, always, nothing.. ( don't take it for granted that these are always wrong, gmat prefers mild tone rather than extreme). Often these answer choices without the extreme word would be the best answer, so we dont look the word and choose the wrong answer. I think the gmat test writers write the correct answer and put some extreme words , and change one or two words here and there and make it more tempting to fall for the trap. Hope this may help you.