Record cuts to teachers and support staff, a significant increase in class sizes and a raft of failings within the Curriculum for Excellence have all contributed to the education crisis, according to the survey.
The findings come as ministers are under increasing pressure over the country's rotten education results, with the latest figures showing a drop in reading and writing performance.
Scots schools have also recorded their worst ever performance in a global study while Education Secretary John Swinney has admitted that cuts to teacher numbers had gone "too far".
Against growing anger about the dramatic collapse, Edinburgh-based political campaigner Mev Brown commissioned a survey of 1,016 Scottish voters.
I commissioned the polling based on the ten most common concerns raised on the doorstep to build a national picture
Mev Brown – Director of EPCResearch
Respected pollster BMG asked 1,016 adults between May 26-29 what they believed were the possible reasons for the falling educational standards in Scotland.
Fifty per cent of people blame poor behaviour and discipline in schools and forty five per cent blame poor parental support and engagement.
Teaching unions have repeatedly said the record cuts to teachers and support staff had led to growing indiscipline in the classroom.
Voters blame Nicola Sturgeon's SNP Government for a collapse in standards in Scottish schools Nicola Sturgeon's comical moments on the campaign trail Mon, May 22, 2017 PA 1 of 13
SNP leader Nicola Sturgeon stops for an ice cream after making an election campaign visit to Scottish Gas HQ in Granton, Edinburgh
In addition to this, the next four most common reasons given for school failings are all directly attributable to the SNP Government.
They are class sizes being too big (41 per cent), quality and standards of teaching (36 per cent), not enough funding (35 per cent) and failings within the Curriculum for Excellence (34 per cent).
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Thirty per cent say a lack of ambition and expectation is a factor, while 24 per cent blame parental drug and alcohol problems.
The standard of school buildings and facilities is blamed by 18 per cent of the electorate, while the lack of support for children who do not speak English is a factor for 12 per cent.
Mr Brown, the director of EPCResearch, said: “I have talked to countless parents, grand parents and younger voters on the doorstep over the last ten years about Scotland's failing education system.
"People have never been backwards about coming forwards regarding their concerns.
"Younger voters talk from recent experience, parents talk from personal experience and grand parents talk about their worries for their grandchildren.
"I commissioned the polling based on the ten most common concerns raised on the doorstep to build a national picture. The results can only be described as a humiliation for the SNP government.
Education Secretary John Swinney has admitted that cuts to teacher numbers had gone 'too far'
"The SNP have been in office for ten years, it might as well be their first day."
He added: "The fact is, Nicola Sturgeon's government have not outlined any concrete policy initiatives to tackle any of the concerns raised by voters on the doorstep.
"Our education system is past a post code lottery, what we have now is survival of the fittest.
"In this regard, Nicola Sturgeon has outlined two policies.
"First, scrap the report that highlighted the failing in Scotland's educational system.
"Second, demand Scotland remain in the EU's single market, guaranteeing freedom of movement.
"This means Scots school leavers failed by the SNP are being sent to the dole queues while better educated EU citizens have unrestricted access to the Scottish jobs market – guaranteed by the SNP.
The poll comes as ministers are under increasing pressure over the country's education results
Scottish Conservative shadow education secretary Liz Smith added: “There are several important reasons why Scotland is slipping back when it comes to school standards.
“The delivery of the Curriculum for Excellence has been a mess. It has meant that teachers have had to focus on far too much unnecessary paperwork at the expense of getting on with the job in the classroom.
“Literacy and numeracy and learning knowledge in the core subjects have all been forced to take a back seat.
“Likewise, the SNP hasn't trained enough teachers. We see shortages right across the country including in some key areas like maths, STEM and additional support needs and we also hear concerns from some teachers that there are gaps in their own training. That is not acceptable.
“For 10 years the SNP has chosen to shelve the necessary reform in education so it's not surprising to see these issues highlighted in this poll.”
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A Scottish Government spokesman said: "This government is committed to providing every child with an equal opportunity to go to college and university and to succeed in life, no matter their circumstances.
"Through the Scottish Attainment Challenge, we are providing ££750 million over the lifetime of this Parliament, to target those children and young people most at need.
"This includes ££120m of Pupil Equity Funding to be spent at the discretion of head teachers and school leaders on additional staffing or resources which they consider will help close the poverty related attainment gap."
Fifty per cent of people questioned blame poor behaviour and discipline in schools
What are the possible reasons for falling educational attainment levels in Scottish schools?
Poor discipline – 50%
Lack of parental support – 45%
Teaching standards – 41%
Class sizes too big – 36%
Not enough funding – 35%
Curriculum for Excellence – 34%
Lack of ambition/expectation – 30%
Parental alcohol/drug problems – 24%
Standard of school buildings and facilities – 18%
Poor support for non-English speakers – 12%
Other countries are improving – 9%
Other – 4%
I don’t believe figures are accurate – 3%
Don’t know – 9%