a) liars will make excessive eye contact because they know that it will help them sell their story. normal chat usually require only around 30-60 percent of oye contact. other than that, liars will blink more frequently too.
b) people who are telling true story tend to skip to other parts of the story and they tend to be demonstrative. liars, on the other hand will construct the story chronologically with many meaningless details.
c) a lying person tend to repeat back the question ask = to buy more tim for them to think.
d) let's be honest, when someone says the previous phrase, there's a chance that they are lying because truthful people doesn't usually need to declare their honesty.
inspired from pamela meyer, author of liespotting