(voiced by
Yeardley Smith ) is a
Fictional Character on the animated
Television series ''
The Simpsons ''.
Matt Groening , the creator of the series, named her after his sister.
Lisa's age is 8 years old; according to her brother
Bart , Lisa is 2 years and 38 days younger than him. This makes her birthday
May 9 th, as Bart's birthday is
April 1 st. She was shown being born during the
1984 Summer Olympics in a flashback episode ("
Lisa's First Word "), but since ''The Simpsons'' characters generally don't age, no specific year for her birth can be given (besides "always" being born "about 8 years ago" except in future-themed episodes).
Lisa is an extremely
Bright girl, with an
IQ of 159 (she is a member of
Mensa , a society for people with high IQs). The first thing she did that showed her intelligence was changing her own
Diaper as an
Infant . Other signs of intelligence at a young age include building a giant castle fort out of
Legos , spelling the word "star" on her letter blocks and putting together a
Jigsaw Puzzle of the
Taj Mahal . Officially, her highest grade is an A++, which she earned by cheating on a test about ''
The Wind In The Willows '' (she later re-marked the test as an F). Once, when she was unable to attend school due to a
Teacher s'
Strike , she suffered a sort of "school withdrawal" and invented a
Perpetual Motion machine; Homer chastised her for this, telling her that in the Simpson household "we obey the
Laws Of Thermodynamics !" She also organized a student strike when she learned
Principal Skinner was exploiting her.
