It is challenging to provide an exact percentage of people who have the intelligence to solve all the puzzles in Portal and Portal 2 unaided, as it depends on various factors:
Individual Differences: Intelligence is a complex and multifaceted trait, and people vary greatly in their problem-solving abilities. Some individuals might excel at spatial reasoning and logical thinking, making it easier for them to solve the puzzles in these games, while others might find it more challenging.
Prior Experience: People with prior experience in playing puzzle-solving games or having exposure to similar concepts might have an advantage in approaching the puzzles in Portal and Portal 2.
Persistence and Determination: The games' puzzles can become increasingly challenging as the player progresses, requiring a high level of persistence, patience, and determination to overcome difficult obstacles.
Learning and Adaptation: The ability to learn from previous attempts and adapt strategies accordingly is essential in solving progressively more complex puzzles.
Time and Effort: Some players might require more time and effort to solve certain puzzles, while others might find quicker solutions based on their cognitive abilities and approach to problem-solving.
Considering these factors, it is difficult to determine an exact percentage. However, both Portal and Portal 2 were designed to provide a challenge to players while also allowing them to gradually learn and improve their problem-solving skills as they progress through the game. The developers aimed to strike a balance between presenting engaging puzzles and making them solvable with effort and critical thinking.
Ultimately, these games are designed to be enjoyable and rewarding experiences, and players of various skill levels can find satisfaction in completing the puzzles, either unaided or with some assistance and guidance.