Wisdom and ignorance, happiness and unhappiness has nothing to do with high intelligence nor low intelligence, Low intelligence doesn’t guarantee kindness, peace and happiness as well. Kindness without non-attachment doesn’t guarantee happiness either.
Happiness is already and always there in oneself. We are disconnected with this happiness when the mind is under the influence of ignorance, egoism, attachment, craving and aversion.
Intelligence and knowledge is neither good nor bad, and has no quality to make anyone happy or unhappy, kind or unkind. We can make use of the intelligence and knowledge to be doing something good or bad for oneself and others, but it also doesn’t guarantee peace and happiness.
Just like a person might have the intelligence, knowledge and skills, to think, to design, to construct, to build a highly ecological and functional beautiful house to live in, but it doesn’t guarantee this person who creates the house, or the people who live in the house will be compassionate, peaceful and happy, be free from being affected, disturbed, influenced or determined by ignorance, selfish desires, egoism, attachment, craving, aversion, pride, arrogance, anger, hatred, greed, dissatisfaction, disappointment, feelings of hurts, fear and worry. And all these defilements has nothing to do with the degree of intelligence and knowledge about this and that.
Real kindness or compassion, peace and happiness, shine in oneself disregards the degree of intelligence and accumulated knowledge, when oneself is free from all these defilements, stop making oneself miserable and unhappy, and stop hurting oneself or others out of these defilements.