The reason is fear. Critics are scared of seeming to drool. So, everything she did was "lovely" or "beautiful", "exquisite" or "pretty" or "exquisitely pretty". But how good an actress was she?
It was a question few critics ever dared to go into. For a start she was the only daughter of an equally beautiful and far more famous mother, the adorable Dorothy Dickson, the toast of Broadway before she moved to London as queen of musical comedy with her husband, Carl Hyson, celebrated exponent of ballroom dancing in an era when it was all the rage.
Whether such parents were a privilege or a setback, Dorothy Hyson rarely appeared outside the West End. Was she once in a try-out at Palmer's Green? Or in a tour that never reached the West End? Perhaps. At any rate her career from the age of three in one of her mother's silent films, and in the West End in a juvenile performance of Barrie's Quality Street went from strength to strength.
Of her appearance aged 13 in Daisy Ashford's The Young Visiters (Strand, 1928) Dame Sybil Thorndike is reported to have assured Dorothy Dickson: "She's got it, hasn't she? She's going to be a star." And James Agate, leading critic of the day and the best judge of acting, prophesied: "I think in Dorothy Hyson we may have the comedienne of the future."
No wonder she never lacked work in plays and films. Did she lack range? Well, to be wanted for straight plays, revues, musical comedy and occasionally the classics argues at least readiness; and with those large eyes, that fair complexion, and attractive voice, Hyson was to become a box-office asset, merely as her mother's daughter.
The trouble about assessing her dramatic as distinct from decorative talent is that she retired from the stage half a century ago. She did so to remarry, raise a family and live, as they say, happily ever after with the long-devoted and much- respected actor-manager and classical director Anthony Quayle, and never came back.
Most pretty young actresses are well advised to go while the going is good, even at 32, since the future for ageing actresses is always less secure than for men; but the going was not only good for Dorothy Hyson but seemed likely to get better after joining Gielgud's Haymarket company in 1945.
No other classical troupe had more prestige. Who knows what would have become of her had she stayed the post-war course?
As an infant whose parents became the toast of Broadway in the First World War, she made her first appearance in one of her mother's silent films, but, unable to cry on cue, she was told by its director: "We thought you would be great. I'm sure you tried hard, but you don't seem to be as good as we thought you would be."
At which tears duly flowed, mother was disgusted, and the girl was put off Hollywood for life. When the parents came to work in London for C.B. Cochran revues in the 1920s, the daughter went to boarding school (with time off for those two juvenile West End plays) and finishing school in Paris before making at 19 an English film with Cicely Courtneidge (Soldiers of the King, 1933). For her professional West End debut in Ivor Novello's play Flies in the Sun (Playhouse 1933) she played a girl whose mother seduced her boyfriend while she was back at school; and, having been rehearsed by both her own mother and the star of the play, Gladys Cooper, she had to endure the first night audience's applause not for her but for the adored mother, sitting conspicuously in a box.
So striking was the mutual resemblance of mother and child that next day when a reporter called on them they were impossible to tell apart. "Miss Hyson entered first. I welcomed her as her mother. Then Miss Dickson came in. I took her for Miss Hyson."
Some time elapsed thereafter before Miss Hyson began to be commended for her acting rather than her looks, if indeed that can ever be said to have happened with Cary Grant having dubbed her "the world's new sweetheart" and Rodgers and Hart having written a song for her, "The Most Beautiful Girl in the World".
Did it matter whether she could act, with such a pleasing appearance and personality? She sang and danced (some said as charmingly as her mother) with Jack Buchanan and Elsie Randolph on screen. She played another bright young thing who tricked an admirer into marriage in another West End play; and if Hyson wasn't the busiest and prettiest actress in London she was surely the loveliest, working by day in films (with Tom Walls and Ralph Lynn from their Aldwych farces) and by night on stage.
Filming at Blackpool with Gracie Fields (Sing As We Go) and acting in the West End as a girl who lured husbands from their wives (Touch Wood, Haymarket, 1934) brought on a nervous breakdown. It did however get her out of the clutches of the autocratic stage and film director Basil Dean, and her acting in the Dodie Smith play prompted thoughts of Hilda Wangel in Ibsen's The Master Builder. Did she have the makings of the actress Agate had dared to anticipate?
Who knows? She never acted Ibsen or Chekhov or even Shakespeare more than once, but no one was busier in light West End comedies and no one had a bigger hit in a Jane Austen adaptation, Pride and Prejudice (St James's, 1936). As Agate put it: "Since everybody in the house was prostrated by the sheer loveliness of her Jane, even when she didn't speak, it was a grovelling evening."
Such grovelling isn't hard for actresses to live with, but what hope have they of fulfilling any dramatic ambition? The classics? All too rarely staged in pre-war days before subsidies.
There came, however in 1938 a chance in Tyrone Guthrie's Old Vic revival of A Midsummer Night's Dream as Titania. A woman critic (significantly or otherwise) dismissed her as "very pretty but rather monotonous".
During the Second World War, Hyson made a few more films (You Will Remember with Robert Morley and Spare A Copper with George Formby, who reputedly attempted her seduction between takes), and acted in intimate revue, musical comedy and straight plays like the thriller Pink String and Sealing Wax (Duke of York's, 1943) and a derivation from Trollope, Scandal at Barchester (Lyric, 1944).
But the "lovely daughter of a lovely mother" theme endured to the end. Even as Lady Windermere in Oscar Wilde's Lady Windermere's Fan in 1945.
"To my mind the best performance of the night was given by exquisite Dorothy Hyson . . . Never for a moment did this lovely daughter of Dorothy Dickson depart from the virginal innocence of a young society hostess in London as untouched by her environment as if she had come straight from a convent."
Another reviewer praised her "courage as well as skill to utter her rigid moral sentiments with a straight face" which she exquisitely "contrived to do with some success," as Wilde's heroine.
It was the critic who had shown such faith in her from the start who sounded a note of warning: "Two ladies wore their tiaras as tiaras should be worn," declared Agate - Hyson evidently not among them - "The rest of the characters, male and female, hadn't the air. What they did was very nice, but it wasn't the Mayfair of those days."
"Lady Windermere should really listen to herself and consider whether personal pronouns do not sound better when they are unstressed." It was Hyson's last role. There are playgoers who still wonder whether she was not on the verge of rising above being her mother's beautiful daughter and becoming a leading classical actress in her own right.
In 1993, as Lady Quayle, widow of Sir Anthony Quayle, hosting a performance celebrating commemorating the life of the actress Dame Peggy Ashcroft, she sat with her son Christopher in the same box at the Playhouse Theatre, London, as her mother Dorothy Dickson, who died in 1995 at the age of 102, had occupied at the same theatre for her daughter's professional stage debut 60 years earlier.
Dorothy Wardell Heisen, actress: born Chicago 24 December 1914; married 1935 Robert Douglas (marriage dissolved 1945), 1947 Anthony Quayle (Kt 1985, died 1989; one son, two daughters); died London 23 May 1996.