Should " the better to hide it from others" be " the better than to hide it from others"?

No. It means self-deception is used to better hide the truth from others. Your suggestion would mean that self-deception is used for reason better than hiding it from others.

Context:

In his book Social Evolution, Robert Trivers enlarged on his
1976 evolutionary theory of self-deception. Self-deception is
hiding the truth from the conscious mind the better to hide it from others. In our own species we recognize that shifty eyes, sweaty palms and croaky voices may indicate the stress that accompanies conscious knowledge of attempted deception. By becoming unconscious of its deception, the deceiver hides these signs from the observer. He or she can lie without the nervousness that
accompanies deception.

What does "others" mean here?

By becoming unconscious of its deception, the deceiver hides these signs from the observer.

oristarA wrote:

What does "others" mean here?

Other people (people other than the self-deceiver).

oristarA wrote:

By becoming unconscious of its deception, the deceiver hides these signs from the observer.

Plus, what does "its" mean? Whose?

contrex wrote:

oristarA wrote:

What does "others" mean here?

Other people (people other than the self-deceiver).

So " the conscious mind" refers to "the conscious mind of the self-deceiver's own"?

oristarA wrote:

contrex wrote:

oristarA wrote:

By becoming unconscious of its deception, the deceiver hides these signs from the observer.

Plus, what does "its" mean? Whose?

The deciever's.

So the author has perticularly reduced the man (who deceives himself) to "it"?
I hear when you call a baby "it", you'd better not let the baby's parents hear you, otherwise you'd be stormed at.

Should " the better to hide it from others" be " the better than to hide it from others"?

oristarA wrote:

oristarA wrote:

contrex wrote:

oristarA wrote:

By becoming unconscious of its deception, the deceiver hides these signs from the observer.

Plus, what does "its" mean? Whose?

The deciever's.

So the author has perticularly reduced the man (who deceives himself) to "it"?
I hear when you call a baby "it", you'd better not let the baby's parents hear you, otherwise you'd be stormed at.

"It's" refers to the deceiver's deception (notice the possessive apostrophe "s" in contrex's reply), not the deceiver himself.

If its deception = the deceiver's deception, it = deceiver. No ambiguity here.

Quote:

Should " the better to hide it from others" be " the better than to hide it from others"?

You've not understood the phrase "all the better to...."

Go back to the tale of Red Riding Hood, which we had recently

(big eyes) "All the better to see you with."
(big ears) "All the better to hear you with"
(big teeth) "All the better to eat you with"

Self-deception is
hiding the truth from the conscious mind the better to hide it from others.

I answered the question you asked, about a grammatical point.
Now you raise something different, which is about the meaning of the sentence.

Quote:

Self-deception is
hiding the truth from the conscious mind the better to hide it from others.

What exactly do you want to know?

If its deception = the deceiver's deception, it = deceiver. No ambiguity here.

Self-deception is hiding the truth from the conscious mind the better to hide it from others.

I answered that already, above.

Quote:

Self-deception is hiding the truth from the conscious mind the better to hide it from others.

And in that sentence, it = truth.

If its deception = the deceiver's deception, it = deceiver. No ambiguity here.

By becoming unconscious of its deception, the deceiver hides these signs from the observer

I see your problem. It is a very awkward and illogocal (and unclear) sentence. I've read it several times, without improving its clarity.

Quote:

By becoming unconscious of its deception, the deceiver hides these signs from the observer

"It" can never refer to a person. It is an impersonal pronoun.
So it's wrong to say it = the deceiver.

It would make better sense if the sentence was written:
By becoming unconscious of THE deception, the deceiver hides these signs from the observer.

I therefore believe the original was in error.