Sensitivity and capacity to tackle deep questions about human existence, such as, what is the meaning of life? Why do we die? How did we get here? etc. is known as Existential Intelligence.
Every person think deeper, about Self existence, at least once in life time, but the One who persistently think and crave for Origin, develop this type of Intelligence. Commonly in teenage stage, go through, phase of such questionnaire, and here is the very important opportunity to inform them . Usually guidance must be done by older and wiser person. Since Existential Intelligence is the Core of all other intelligences, by developing this, we are watering the Roots.
In all religions usually rituals are there, to initiate such learning. Existential Intelligence is the Spiritual journey. In Indian Philosophical literature, at the age of 7, this teaching is initiated by doing the ritual called as Maunj , and is done so by Gayatri Mantra . Then the child is ready to go to Gurukul, to learn. Gradually narrating the traditional stories which explain the formation of our very Earth, Plant Kingdom, Animal Kingdom, Evolution process in Human beings and the most important information about the God and Oneness of His Existence!
Let the child, young one ask questions , parents should try to answer, but it's always advisable, that, the learned one must guide, to avoid misconception. Reading and group discussion amongst wise people can enhance this Existential Intelligence.
The Ved, Upanishad, Geeta, the Holy Quran, the Holy Bible, the Granth Sahib, the PanchSheel of Tathagat Buddha, are the Enlighten Books, which lead to enhancement of Existential Intelligence. Aham Bramhasmi is the Soham practice to attend , Existential experience with the grace of Sadguru, and is known as highest of Existential Intelligence.