Final answer:
Joe's weakness is language comprehension and use, indicating a learning disability in language. Such disabilities do not reflect overall intelligence and require specific accommodations and support for improvement.
Step-by-step explanation:
The skill that Joe, a teenager, is struggling with, in the context of intellectual disability, is likely related to language comprehension and use. His history of poor performances in language-based subjects since childhood suggests a learning disability that specifically affects his ability to understand or use language. Such disabilities are characterized by a discrepancy between a person's overall intelligence and their abilities in a specific domain, meaning that while Joe may have average or above-average intelligence, he has a deficit in language skills which affects his academic performance.
Learning disabilities like dysgraphia, dyslexia, and dyscalculia tend to be highly specific and do not represent global deficiencies in intelligence. These disabilities can coexist with other disorders such as ADHD, and individuals with learning disabilities may require specific accommodations to succeed in school. For Joe, identifying the precise nature of his language difficulties and providing appropriate support and interventions will be crucial to helping him improve his academic performance.