I just finished a special issue on 'Humans - Why we're unlike any other species on the planet' (Sci Am, September 2018).
In this issue, Kevin Laland has a paper (How we became a different kind of animal) and he nicely abstracts the answer to your question in your question title: Why are we the smartest species on the whole known universe?, namely:
- Human accomplishments derive from our ability to acquire knowledge from others and to use that communal store of experience to devise novel solutions to life's challenges.
- Other species innovate, too. Chimps open nuts with stone hammers. Dolphins use a tool to flush out hidden prey.
- Our uniqueness has to do with a capacity to teach skills to others over the generations with enough precision for building skyscrapers or going to the moon.
Now, relating to your question body's focus, What [is the] evolutionary advantage [of] having [a] high "intelligence" [for] humans?
In that same special issue, Chet C. Sherwood explains this question in his contribution 'Are we wired differently? by saying:
Modern human brains are about threefold larger than those of our closest hominin acestors . [T]he parts of the cerebral cortex involved in higher-order cognitive functions, such as creativity and abstract thinking, have become especially enlarged. These [...] association regions [...] are loci for language, toolmaking and imitation.
Now, that last sentence couples the two papers nicely - we need that bigger brain to allow us to use language and imitation to be able to teach and learn, respectively.
Your next question, regarding that My friend told me that the greatest benefit of intelligence is that we "deceive" others betters - Now that is exactly what is not the consensus as of now.
Thomas Suddendorf, again in that same special issue explains in his paper 'Two key features created the human mind':
Why are we, and not gorillas, running the zoos? [...]. Research has revealed two distinct human features: complex scenario building and exchanging thoughts with others.Together these traits underlie critical human capacities such as language, culture., [and] morality [...].
Michael Tomasello, [yes, again that same issue], explains in his paper The Origins of Human Morality - How we learned to put our fate in one another’s hands:
[...] [S]ituations of reciprocity can arise in which I scratch your back and you scratch mine and we both benefit in the long run.
While chimps may hunt together, when the bounty has been found and captured, the feeding is an individual matter. In contrast, humans have the tendency to take care for the group, and share food. Taking care of the group eventually pays itself of, as the group will take care of you. This is enhanced by the sense of morality, in which you will do no harm to others. If you do, you will be excluded from the group, and no one will scratch your back.
Seeds of human morality were planted some 400,000 years ago, when individuals began to collaborate in hunting-and-gathering exploits.
- Special issue of Sci Am, September 2018