Writing someone else's memoir is referred to as "writing a biography rather than a memoir." After all, you are not the topic. You are the vehicle through which the subject of the book is presented to the reader. The writer must determine how to best convey information about someone else into words.
Generally speaking, yes, a memoir can be written by another person. However, there are many factors that may affect what kind of book emerges from the process. For example: if the writer uses their subject's own words without giving them credit, this could be considered plagiarism. Also, if the writer makes substantial changes to the text or adds new material- especially if it includes the author's interpretation of their subject's life- then this might influence some readers to label the work a biography instead of a memoir.
As long as you adhere to these basic guidelines, you should have no problems writing a successful memoir.
The first thing to understand is that a memoir is not exactly like other kinds of books. Memoirs are unique stories that often include the experiences of the author but sometimes also include those of others. Thus, they cannot be simply categorized as fiction or non-fiction.
A biography of a person, written by or as if written by that person. It may have been written by someone else.
Autobiographies are written by individuals for themselves or for others. They can be self-published or published by a company. Writing an autobiography can be a very personal and meaningful experience for the writer. The genre is widely accepted in Europe but not in America. In France it is called "auto-biographie" and there are even magazines devoted to this subject matter.
In England, Australia and New Zealand writers call their autobiographies "memoirs".
The term "autobiography" was invented by the Greek historian Herodotus (c. 484 B.C.- c. 424 B.C.) in his work The History. He was the first person to use this word to describe a writing about himself. Before him, people had used the terms "life" or "history" instead. Today we know Herodotus' definition of autobiography: "a history of one's own life."
Herodotus wrote in the form of speeches by famous ancient Greeks which made them sound like articles written by different people. This is how he got their opinions on current events.
Simply simply, a biography is someone else's account of an individual's life. An autobiography is the written account of a person's life. A memoir is a collection of memories written by the author. All three are forms of biographies.
All biography texts examine and interpret the life of another in order to understand more about themselves or their world. However, they do so in very different ways. Biography can be written by historians, psychologists, journalists, and others. The only requirement is that the writer has access to the subject's personal papers or other important evidence about his or her life.
There are many types of biography. Official documents such as birth certificates, marriage licenses, and death certificates; literary works such as novels and poems; and autobiographical writings such as diaries and letters make up the main sources for biography. Historians use these same sources to learn more about past people and events. Biographers often draw on several of these types of evidence when writing their works. For example, they may include information about the life of their subject found in official records and in literary books about them too. This allows them to provide more detail about their subjects' lives than would be possible if they were limited to one source type.